diff --git a/CHANGELOG.md b/CHANGELOG.md
index 653ef899e4..ad82a96850 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # 1.1.0-beta.x
 
+- Inject and use SignedExtensions by name from V11 metadata (V4 extrinsics only)
 - Add typings for `api.tx.*.*` - the `polkadot-types-from-chain` now also generates these
 - Remove additional V1-only derives `(staking.recentlyOffline`, `balances.nominatorsFor`)
 
diff --git a/packages/api/src/base/Init.ts b/packages/api/src/base/Init.ts
index a993b592c5..55adae5153 100644
--- a/packages/api/src/base/Init.ts
+++ b/packages/api/src/base/Init.ts
@@ -128,9 +128,12 @@ export default abstract class Init<ApiType extends ApiTypes> extends Decorate<Ap
     this.registerTypes(getMetadataTypes(metadata.version));
 
     const decoratedMeta = new DecoratedMeta(this.registry, metadata);
+    const metaExtrinsic = metadata.asLatest.extrinsic;
 
     // only inject if we are not a clone (global init)
-    if (!this._options.source) {
+    if (metaExtrinsic.version.gtn(0)) {
+      this._extrinsicType = metaExtrinsic.version.toNumber();
+    } else if (!this._options.source) {
       // detect the extrinsic version in-use based on the last block
       const { block: { extrinsics: [firstTx] } }: SignedBlock = await this._rpcCore.chain.getBlock().toPromise();
 
diff --git a/packages/api/src/promise/Api.spec.ts b/packages/api/src/promise/Api.spec.ts
index aa587b48d1..da45cc6663 100644
--- a/packages/api/src/promise/Api.spec.ts
+++ b/packages/api/src/promise/Api.spec.ts
@@ -122,10 +122,13 @@ describe('ApiPromise', (): void => {
       const api = await ApiPromise.create({ provider, registry, signer });
       const transfer = api.tx.balances.transfer(keyring.getPair('0xe659a7a1628cdd93febc04a4e0646ea20e9f5f0ce097d9a05290d4a9e054df4e').address, 12345);
 
-      await transfer.signAsync(aliceEd, {});
+      await transfer.signAsync(aliceEd.address, {});
 
       expect(transfer.signature.toHex()).toEqual(
-        '0x6b9ccc95afbd4e916d30c65c720f4f7b70a77db545735b48a763844aa5210e695aa346686bad1224af77d00bcfbf6fc8d2c216a60731027835d5a414186a2607'
+        // v1 extrinsic
+        // '0x6b9ccc95afbd4e916d30c65c720f4f7b70a77db545735b48a763844aa5210e695aa346686bad1224af77d00bcfbf6fc8d2c216a60731027835d5a414186a2607'
+        // v4 extrinsic
+        '0x0716cbdc3b649dad8741238bcc8e4336f859c518cf2b17a3427b2f5d0b8a79cf518da71b9ac71d92c517342e0978f297f5e05362babf5987d3f1c5ba3314af08'
       );
     });
   });
diff --git a/packages/types/src/codec/AbstractInt.ts b/packages/types/src/codec/AbstractInt.ts
index cacd4529a4..93c47f6bb3 100644
--- a/packages/types/src/codec/AbstractInt.ts
+++ b/packages/types/src/codec/AbstractInt.ts
@@ -39,6 +39,7 @@ export default abstract class AbstractInt extends BN implements Codec {
     this._isNegative = isNegative;
   }
 
+  /** @internal */
   public static decodeAbstracInt (value: AnyNumber, bitLength: UIntBitLength, isNegative: boolean): string {
     // This function returns a string, which will be passed in the BN
     // constructor. It would be ideal to actually return a BN, but there's a
@@ -54,6 +55,7 @@ export default abstract class AbstractInt extends BN implements Codec {
     return bnToBn(value).toString();
   }
 
+  /** @internal */
   private static decodeAbstracIntU8a (value: Uint8Array, bitLength: UIntBitLength, isNegative: boolean): string {
     if (!value.length) {
       return '0';
diff --git a/packages/types/src/codec/BTreeMap.ts b/packages/types/src/codec/BTreeMap.ts
index 87d26eaee7..54f660757e 100644
--- a/packages/types/src/codec/BTreeMap.ts
+++ b/packages/types/src/codec/BTreeMap.ts
@@ -42,6 +42,7 @@ export default class BTreeMap<K extends Codec = Codec, V extends Codec = Codec>
    * - Map<any, any>, where both key and value types are either
    *   constructors or decodeable values for their types.
    * @param jsonMap
+   * @internal
    */
   private static decodeBTreeMap<K extends Codec = Codec, V extends Codec = Codec> (registry: Registry, KeyClass: Constructor<K>, ValClass: Constructor<V>, value: Uint8Array | string | Map<any, any>): Map<K, V> {
     if (!value) {
@@ -57,6 +58,7 @@ export default class BTreeMap<K extends Codec = Codec, V extends Codec = Codec>
     throw new Error('BTreeMap: cannot decode type');
   }
 
+  /** @internal */
   private static decodeBTreeMapFromU8a<K extends Codec = Codec, V extends Codec = Codec> (registry: Registry, KeyClass: Constructor<K>, ValClass: Constructor<V>, u8a: Uint8Array): Map<K, V> {
     const output = new Map<K, V>();
     const [offset, length] = Compact.decodeU8a(u8a);
@@ -75,6 +77,7 @@ export default class BTreeMap<K extends Codec = Codec, V extends Codec = Codec>
     return output;
   }
 
+  /** @internal */
   private static decodeBTreeMapFromMap<K extends Codec = Codec, V extends Codec = Codec> (registry: Registry, KeyClass: Constructor<K>, ValClass: Constructor<V>, value: Map<any, any>): Map<K, V> {
     const output = new Map<K, V>();
 
diff --git a/packages/types/src/codec/BTreeSet.ts b/packages/types/src/codec/BTreeSet.ts
index 7cfab93982..f578e7c139 100644
--- a/packages/types/src/codec/BTreeSet.ts
+++ b/packages/types/src/codec/BTreeSet.ts
@@ -37,6 +37,7 @@ export default class BTreeSet<V extends Codec = Codec> extends Set<V> implements
    * - Set<any>, where both key and value types are either
    *   constructors or decodeable values for their types.
    * @param jsonSet
+   * @internal
    */
   private static decodeBTreeSet<V extends Codec = Codec> (registry: Registry, ValClass: Constructor<V>, value: Uint8Array | string | Set<any>): Set<V> {
     if (!value) {
@@ -52,6 +53,7 @@ export default class BTreeSet<V extends Codec = Codec> extends Set<V> implements
     throw new Error('BTreeSet: cannot decode type');
   }
 
+  /** @internal */
   private static decodeBTreeSetFromU8a<V extends Codec = Codec> (registry: Registry, ValClass: Constructor<V>, u8a: Uint8Array): Set<V> {
     const output = new Set<V>();
     const [offset, length] = Compact.decodeU8a(u8a);
@@ -70,6 +72,7 @@ export default class BTreeSet<V extends Codec = Codec> extends Set<V> implements
     return output;
   }
 
+  /** @internal */
   private static decodeBTreeSetFromSet<V extends Codec = Codec> (registry: Registry, ValClass: Constructor<V>, value: Set<any>): Set<V> {
     const output = new Set<V>();
 
diff --git a/packages/types/src/codec/Compact.ts b/packages/types/src/codec/Compact.ts
index 146f11a463..fbea690ec2 100644
--- a/packages/types/src/codec/Compact.ts
+++ b/packages/types/src/codec/Compact.ts
@@ -56,6 +56,7 @@ export default class Compact<T extends CompactEncodable> extends Base<T> impleme
     return value;
   }
 
+  /** @internal */
   public static decodeCompact<T extends CompactEncodable> (registry: Registry, Type: Constructor<T>, value: Compact<T> | AnyNumber): CompactEncodable {
     if (value instanceof Compact) {
       return new Type(registry, value.raw);
diff --git a/packages/types/src/codec/Date.ts b/packages/types/src/codec/Date.ts
index f0968273dc..77401243e7 100644
--- a/packages/types/src/codec/Date.ts
+++ b/packages/types/src/codec/Date.ts
@@ -35,6 +35,7 @@ export default class CodecDate extends Date implements Codec {
     this.raw = this;
   }
 
+  /** @internal */
   public static decodeDate (value: CodecDate | Date | AnyNumber): Date {
     if (value instanceof Date) {
       return value;
diff --git a/packages/types/src/codec/Enum.ts b/packages/types/src/codec/Enum.ts
index ba5ef8cc23..c25f9abf09 100644
--- a/packages/types/src/codec/Enum.ts
+++ b/packages/types/src/codec/Enum.ts
@@ -121,6 +121,7 @@ export default class Enum extends Base<Codec> {
     this._index = this._indexes.indexOf(decoded.index) || 0;
   }
 
+  /** @internal */
   private static decodeEnum (registry: Registry, def: TypesDef, value?: any, index?: number): Decoded {
     // NOTE We check the index path first, before looking at values - this allows treating
     // the optional indexes before anything else, more-specific > less-specific
diff --git a/packages/types/src/codec/Option.ts b/packages/types/src/codec/Option.ts
index cbd8dcbd79..d7944f6bd2 100644
--- a/packages/types/src/codec/Option.ts
+++ b/packages/types/src/codec/Option.ts
@@ -29,6 +29,7 @@ export default class Option<T extends Codec> extends Base<T> {
     this._Type = Clazz;
   }
 
+  /** @internal */
   public static decodeOption (registry: Registry, Type: Constructor, value?: any): Codec {
     if (isNull(value) || isUndefined(value) || value instanceof Null) {
       return new Null(registry);
@@ -46,6 +47,7 @@ export default class Option<T extends Codec> extends Base<T> {
     return new Type(registry, value);
   }
 
+  /** @internal */
   private static decodeOptionU8a (registry: Registry, Type: Constructor, value: Uint8Array): Codec {
     return !value.length || value[0] === 0
       ? new Null(registry)
diff --git a/packages/types/src/codec/Raw.ts b/packages/types/src/codec/Raw.ts
index af07ff9ff9..9c6efc016e 100644
--- a/packages/types/src/codec/Raw.ts
+++ b/packages/types/src/codec/Raw.ts
@@ -25,6 +25,7 @@ export default class Raw extends Uint8Array implements IU8a {
     this.registry = registry;
   }
 
+  /** @internal */
   private static decodeU8a (value?: any): Uint8Array {
     if (isU8a(value)) {
       return value;
diff --git a/packages/types/src/codec/Set.ts b/packages/types/src/codec/Set.ts
index cf136d4486..dee4925dbd 100644
--- a/packages/types/src/codec/Set.ts
+++ b/packages/types/src/codec/Set.ts
@@ -32,6 +32,7 @@ export default class CodecSet extends Set<string> implements Codec {
     this._setValues = setValues;
   }
 
+  /** @internal */
   public static decodeSet (setValues: SetValues, value: string[] | Set<string> | Uint8Array | BN | number | string = 0): string[] {
     if (isString(value)) {
       return CodecSet.decodeSet(setValues, u8aToU8a(value));
@@ -48,6 +49,7 @@ export default class CodecSet extends Set<string> implements Codec {
     return CodecSet.decodeSetNumber(setValues, value);
   }
 
+  /** @internal */
   private static decodeSetArray (setValues: SetValues, value: string[]): string[] {
     return value.reduce((result, key): string[] => {
       assert(!isUndefined(setValues[key]), `Set: Invalid key '${key}' passed to Set, allowed ${Object.keys(setValues).join(', ')}`);
@@ -58,6 +60,7 @@ export default class CodecSet extends Set<string> implements Codec {
     }, [] as string[]);
   }
 
+  /** @internal */
   private static decodeSetNumber (setValues: SetValues, _value: BN | number): string[] {
     const bn = bnToBn(_value);
     const result = Object.keys(setValues).reduce((result, key): string[] => {
diff --git a/packages/types/src/codec/Struct.ts b/packages/types/src/codec/Struct.ts
index 9a6e2f3de3..26dda6f6a7 100644
--- a/packages/types/src/codec/Struct.ts
+++ b/packages/types/src/codec/Struct.ts
@@ -62,6 +62,7 @@ export default class Struct<
    * - array with `[value1, value2]` assuming the array has the same length as
    * `Object.keys(Types)`
    * @param jsonMap
+   * @internal
    */
   private static decodeStruct <T> (registry: Registry, Types: ConstructorDef, value: any, jsonMap: Map<any, string>): T {
     if (isHex(value)) {
@@ -84,6 +85,7 @@ export default class Struct<
     return Struct.decodeStructFromObject(registry, Types, value, jsonMap);
   }
 
+  /** @internal */
   private static decodeStructFromObject <T> (registry: Registry, Types: ConstructorDef, value: any, jsonMap: Map<any, string>): T {
     return Object.keys(Types).reduce((raw, key, index): T => {
       // The key in the JSON can be snake_case (or other cases), but in our
diff --git a/packages/types/src/codec/StructAny.ts b/packages/types/src/codec/StructAny.ts
index 945bb8813c..584947e736 100644
--- a/packages/types/src/codec/StructAny.ts
+++ b/packages/types/src/codec/StructAny.ts
@@ -43,6 +43,7 @@ export default class StructAny extends Map<string, any> implements Codec {
     });
   }
 
+  /** @internal */
   private static decodeJson (value?: { [index: string]: any } | null): [string, any][] {
     return Object.entries(value || {});
   }
diff --git a/packages/types/src/codec/Tuple.ts b/packages/types/src/codec/Tuple.ts
index 622df869eb..5f5018a5b1 100644
--- a/packages/types/src/codec/Tuple.ts
+++ b/packages/types/src/codec/Tuple.ts
@@ -36,6 +36,7 @@ export default class Tuple extends AbstractArray<Codec> {
     this._Types = Clazzes;
   }
 
+  /** @internal */
   private static decodeTuple (registry: Registry, _Types: TupleConstructors, value: AnyU8a | string | (AnyU8a | AnyNumber | AnyString | undefined | null)[]): Codec[] {
     if (isU8a(value)) {
       return decodeU8a(registry, value, _Types);
diff --git a/packages/types/src/codec/U8aFixed.ts b/packages/types/src/codec/U8aFixed.ts
index f24d968af7..1ee958c1cb 100644
--- a/packages/types/src/codec/U8aFixed.ts
+++ b/packages/types/src/codec/U8aFixed.ts
@@ -24,6 +24,7 @@ export default class U8aFixed extends Raw {
     super(registry, U8aFixed.decodeU8aFixed(value, bitLength));
   }
 
+  /** @internal */
   private static decodeU8aFixed (value: AnyU8a, bitLength: BitLength): AnyU8a {
     if (Array.isArray(value) || isString(value)) {
       return U8aFixed.decodeU8aFixed(u8aToU8a(value), bitLength);
diff --git a/packages/types/src/codec/Vec.ts b/packages/types/src/codec/Vec.ts
index 8f6f95cdd5..321e8e0b43 100644
--- a/packages/types/src/codec/Vec.ts
+++ b/packages/types/src/codec/Vec.ts
@@ -30,6 +30,7 @@ export default class Vec<T extends Codec> extends AbstractArray<T> {
     this._Type = Clazz;
   }
 
+  /** @internal */
   public static decodeVec<T extends Codec> (registry: Registry, Type: Constructor<T>, value: Vec<any> | Uint8Array | string | any[]): T[] {
     if (Array.isArray(value)) {
       return value.map((entry, index): T => {
diff --git a/packages/types/src/codec/VecFixed.ts b/packages/types/src/codec/VecFixed.ts
index 24f34af876..3d7460b5c0 100644
--- a/packages/types/src/codec/VecFixed.ts
+++ b/packages/types/src/codec/VecFixed.ts
@@ -25,6 +25,7 @@ export default class VecFixed<T extends Codec> extends AbstractArray<T> {
     this._Type = Clazz;
   }
 
+  /** @internal */
   public static decodeVecFixed<T extends Codec> (registry: Registry, Type: Constructor<T>, allocLength: number, value: VecFixed<any> | Uint8Array | string | any[]): T[] {
     const values = Vec.decodeVec(
       registry,
diff --git a/packages/types/src/codec/create/registry.ts b/packages/types/src/codec/create/registry.ts
index 7394919bcd..4a1e52f48a 100644
--- a/packages/types/src/codec/create/registry.ts
+++ b/packages/types/src/codec/create/registry.ts
@@ -3,13 +3,14 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { CallFunction, Codec, Constructor, RegistryError, RegistryTypes, Registry, RegistryMetadata, TypeDef } from '../../types';
+import { CallFunction, Codec, Constructor, InterfaceTypes, RegistryError, RegistryTypes, Registry, RegistryMetadata, TypeDef } from '../../types';
 
 import extrinsicsFromMeta from '@polkadot/metadata/Decorated/extrinsics/fromMetadata';
 import { assert, isFunction, isString, isUndefined, stringCamelCase, u8aToHex } from '@polkadot/util';
 
 import Raw from '../Raw';
 import { EventData } from '../../primitive/Generic/Event';
+import { defaultExtensions, expandExtensionTypes } from '../../primitive/Extrinsic/SignedExtensions';
 import { createClass } from './createClass';
 import { getTypeClass } from './getTypeClass';
 import { getTypeDef } from './getTypeDef';
@@ -85,6 +86,8 @@ export class TypeRegistry implements Registry {
 
   private _metadataEvents: Record<string, Constructor<EventData>> = {};
 
+  private _metadataExtensions: string[] = defaultExtensions;
+
   constructor () {
     // we only want to import these on creation, i.e. we want to avoid types
     // weird side-effects from circular references. (Since registry is injected
@@ -165,6 +168,14 @@ export class TypeRegistry implements Registry {
     return type;
   }
 
+  public getSignedExtensionExtra (): Record<string, InterfaceTypes> {
+    return expandExtensionTypes(this._metadataExtensions, 'extra');
+  }
+
+  public getSignedExtensionTypes (): Record<string, InterfaceTypes> {
+    return expandExtensionTypes(this._metadataExtensions, 'types');
+  }
+
   public hasClass (name: string): boolean {
     return this._classes.has(name);
   }
@@ -221,5 +232,10 @@ export class TypeRegistry implements Registry {
     decorateExtrinsics(this, metadata, this._metadataCalls);
     decorateErrors(this, metadata, this._metadataErrors);
     decorateEvents(this, metadata, this._metadataEvents);
+
+    // setup the available extensions
+    this._metadataExtensions = metadata.asLatest.extrinsic.version.gtn(0)
+      ? metadata.asLatest.extrinsic.signedExtensions.map((key): string => key.toString())
+      : defaultExtensions;
   }
 }
diff --git a/packages/types/src/interfaceRegistry.ts b/packages/types/src/interfaceRegistry.ts
index 0653d9873f..9d25715d82 100644
--- a/packages/types/src/interfaceRegistry.ts
+++ b/packages/types/src/interfaceRegistry.ts
@@ -3,7 +3,7 @@
 
 import { Compact, Option, Raw, Vec } from '@polkadot/types/codec';
 import { Bytes, Data, Fixed64, H160, H256, H512, IdentityFields, Null, StorageData, StorageKey, Text, Type, U256, bool, i128, i16, i256, i32, i64, i8, u128, u16, u256, u32, u64, u8, usize } from '@polkadot/types/primitive';
-import { AccountId, AccountIdOf, AccountIndex, Address, AssetId, Balance, BalanceOf, Block, BlockNumber, Call, ChangesTrieConfiguration, Consensus, ConsensusEngineId, Digest, DigestItem, DispatchClass, DispatchInfo, DispatchInfoTo190, EcdsaSignature, Ed25519Signature, Extrinsic, ExtrinsicEra, ExtrinsicPayload, ExtrinsicPayloadUnknown, ExtrinsicPayloadV1, ExtrinsicPayloadV2, ExtrinsicPayloadV3, ExtrinsicPayloadV4, ExtrinsicUnknown, ExtrinsicV1, ExtrinsicV2, ExtrinsicV3, ExtrinsicV4, Hash, Header, ImmortalEra, Index, Justification, KeyTypeId, KeyValue, LockIdentifier, Moment, MortalEra, MultiSignature, Origin, Perbill, Percent, Permill, Perquintill, Phantom, PhantomData, PreRuntime, Seal, SealV0, Signature, SignedBlock, SignerPayload, Sr25519Signature, ValidatorId, Weight, WeightMultiplier } from '@polkadot/types/interfaces/runtime';
+import { AccountId, AccountIdOf, AccountIndex, Address, AssetId, Balance, BalanceOf, Block, BlockNumber, Call, ChangesTrieConfiguration, Consensus, ConsensusEngineId, Digest, DigestItem, DispatchClass, DispatchInfo, DispatchInfoTo190, EcdsaSignature, Ed25519Signature, Extrinsic, ExtrinsicEra, ExtrinsicPayload, ExtrinsicPayloadUnknown, ExtrinsicPayloadV1, ExtrinsicPayloadV2, ExtrinsicPayloadV3, ExtrinsicPayloadV4, ExtrinsicSignatureV1, ExtrinsicSignatureV2, ExtrinsicSignatureV3, ExtrinsicSignatureV4, ExtrinsicUnknown, ExtrinsicV1, ExtrinsicV2, ExtrinsicV3, ExtrinsicV4, Hash, Header, ImmortalEra, Index, Justification, KeyTypeId, KeyValue, LockIdentifier, Moment, MortalEra, MultiSignature, Origin, Perbill, Percent, Permill, Perquintill, Phantom, PhantomData, PreRuntime, Seal, SealV0, Signature, SignedBlock, SignerPayload, Sr25519Signature, ValidatorId, Weight, WeightMultiplier } from '@polkadot/types/interfaces/runtime';
 import { InclusionHeight, Uncle, UncleEntryItem } from '@polkadot/types/interfaces/authorship';
 import { RawAuraPreDigest } from '@polkadot/types/interfaces/aura';
 import { BabeAuthorityWeight, BabeBlockWeight, BabeWeight, MaybeVrf, RawBabePreDigest, RawBabePreDigestCompat, RawBabePreDigestPrimary, RawBabePreDigestPrimaryTo159, RawBabePreDigestSecondary, RawBabePreDigestSecondaryTo159, RawBabePreDigestTo159, SlotNumber, VrfData, VrfProof } from '@polkadot/types/interfaces/babe';
@@ -127,6 +127,57 @@ export interface InterfaceRegistry {
   Raw: Raw;
   'Option<Raw>': Option<Raw>;
   'Vec<Raw>': Vec<Raw>;
+  Extrinsic: Extrinsic;
+  'Option<Extrinsic>': Option<Extrinsic>;
+  'Vec<Extrinsic>': Vec<Extrinsic>;
+  ExtrinsicEra: ExtrinsicEra;
+  'Option<ExtrinsicEra>': Option<ExtrinsicEra>;
+  'Vec<ExtrinsicEra>': Vec<ExtrinsicEra>;
+  ExtrinsicPayload: ExtrinsicPayload;
+  'Option<ExtrinsicPayload>': Option<ExtrinsicPayload>;
+  'Vec<ExtrinsicPayload>': Vec<ExtrinsicPayload>;
+  ExtrinsicV1: ExtrinsicV1;
+  'Option<ExtrinsicV1>': Option<ExtrinsicV1>;
+  'Vec<ExtrinsicV1>': Vec<ExtrinsicV1>;
+  ExtrinsicPayloadV1: ExtrinsicPayloadV1;
+  'Option<ExtrinsicPayloadV1>': Option<ExtrinsicPayloadV1>;
+  'Vec<ExtrinsicPayloadV1>': Vec<ExtrinsicPayloadV1>;
+  ExtrinsicSignatureV1: ExtrinsicSignatureV1;
+  'Option<ExtrinsicSignatureV1>': Option<ExtrinsicSignatureV1>;
+  'Vec<ExtrinsicSignatureV1>': Vec<ExtrinsicSignatureV1>;
+  ExtrinsicV2: ExtrinsicV2;
+  'Option<ExtrinsicV2>': Option<ExtrinsicV2>;
+  'Vec<ExtrinsicV2>': Vec<ExtrinsicV2>;
+  ExtrinsicPayloadV2: ExtrinsicPayloadV2;
+  'Option<ExtrinsicPayloadV2>': Option<ExtrinsicPayloadV2>;
+  'Vec<ExtrinsicPayloadV2>': Vec<ExtrinsicPayloadV2>;
+  ExtrinsicSignatureV2: ExtrinsicSignatureV2;
+  'Option<ExtrinsicSignatureV2>': Option<ExtrinsicSignatureV2>;
+  'Vec<ExtrinsicSignatureV2>': Vec<ExtrinsicSignatureV2>;
+  ExtrinsicV3: ExtrinsicV3;
+  'Option<ExtrinsicV3>': Option<ExtrinsicV3>;
+  'Vec<ExtrinsicV3>': Vec<ExtrinsicV3>;
+  ExtrinsicPayloadV3: ExtrinsicPayloadV3;
+  'Option<ExtrinsicPayloadV3>': Option<ExtrinsicPayloadV3>;
+  'Vec<ExtrinsicPayloadV3>': Vec<ExtrinsicPayloadV3>;
+  ExtrinsicSignatureV3: ExtrinsicSignatureV3;
+  'Option<ExtrinsicSignatureV3>': Option<ExtrinsicSignatureV3>;
+  'Vec<ExtrinsicSignatureV3>': Vec<ExtrinsicSignatureV3>;
+  ExtrinsicV4: ExtrinsicV4;
+  'Option<ExtrinsicV4>': Option<ExtrinsicV4>;
+  'Vec<ExtrinsicV4>': Vec<ExtrinsicV4>;
+  ExtrinsicPayloadV4: ExtrinsicPayloadV4;
+  'Option<ExtrinsicPayloadV4>': Option<ExtrinsicPayloadV4>;
+  'Vec<ExtrinsicPayloadV4>': Vec<ExtrinsicPayloadV4>;
+  ExtrinsicSignatureV4: ExtrinsicSignatureV4;
+  'Option<ExtrinsicSignatureV4>': Option<ExtrinsicSignatureV4>;
+  'Vec<ExtrinsicSignatureV4>': Vec<ExtrinsicSignatureV4>;
+  ExtrinsicUnknown: ExtrinsicUnknown;
+  'Option<ExtrinsicUnknown>': Option<ExtrinsicUnknown>;
+  'Vec<ExtrinsicUnknown>': Vec<ExtrinsicUnknown>;
+  ExtrinsicPayloadUnknown: ExtrinsicPayloadUnknown;
+  'Option<ExtrinsicPayloadUnknown>': Option<ExtrinsicPayloadUnknown>;
+  'Vec<ExtrinsicPayloadUnknown>': Vec<ExtrinsicPayloadUnknown>;
   AccountId: AccountId;
   'Option<AccountId>': Option<AccountId>;
   'Vec<AccountId>': Vec<AccountId>;
@@ -183,45 +234,6 @@ export interface InterfaceRegistry {
   DispatchInfoTo190: DispatchInfoTo190;
   'Option<DispatchInfoTo190>': Option<DispatchInfoTo190>;
   'Vec<DispatchInfoTo190>': Vec<DispatchInfoTo190>;
-  Extrinsic: Extrinsic;
-  'Option<Extrinsic>': Option<Extrinsic>;
-  'Vec<Extrinsic>': Vec<Extrinsic>;
-  ExtrinsicEra: ExtrinsicEra;
-  'Option<ExtrinsicEra>': Option<ExtrinsicEra>;
-  'Vec<ExtrinsicEra>': Vec<ExtrinsicEra>;
-  ExtrinsicPayload: ExtrinsicPayload;
-  'Option<ExtrinsicPayload>': Option<ExtrinsicPayload>;
-  'Vec<ExtrinsicPayload>': Vec<ExtrinsicPayload>;
-  ExtrinsicPayloadUnknown: ExtrinsicPayloadUnknown;
-  'Option<ExtrinsicPayloadUnknown>': Option<ExtrinsicPayloadUnknown>;
-  'Vec<ExtrinsicPayloadUnknown>': Vec<ExtrinsicPayloadUnknown>;
-  ExtrinsicPayloadV1: ExtrinsicPayloadV1;
-  'Option<ExtrinsicPayloadV1>': Option<ExtrinsicPayloadV1>;
-  'Vec<ExtrinsicPayloadV1>': Vec<ExtrinsicPayloadV1>;
-  ExtrinsicPayloadV2: ExtrinsicPayloadV2;
-  'Option<ExtrinsicPayloadV2>': Option<ExtrinsicPayloadV2>;
-  'Vec<ExtrinsicPayloadV2>': Vec<ExtrinsicPayloadV2>;
-  ExtrinsicPayloadV3: ExtrinsicPayloadV3;
-  'Option<ExtrinsicPayloadV3>': Option<ExtrinsicPayloadV3>;
-  'Vec<ExtrinsicPayloadV3>': Vec<ExtrinsicPayloadV3>;
-  ExtrinsicPayloadV4: ExtrinsicPayloadV4;
-  'Option<ExtrinsicPayloadV4>': Option<ExtrinsicPayloadV4>;
-  'Vec<ExtrinsicPayloadV4>': Vec<ExtrinsicPayloadV4>;
-  ExtrinsicUnknown: ExtrinsicUnknown;
-  'Option<ExtrinsicUnknown>': Option<ExtrinsicUnknown>;
-  'Vec<ExtrinsicUnknown>': Vec<ExtrinsicUnknown>;
-  ExtrinsicV1: ExtrinsicV1;
-  'Option<ExtrinsicV1>': Option<ExtrinsicV1>;
-  'Vec<ExtrinsicV1>': Vec<ExtrinsicV1>;
-  ExtrinsicV2: ExtrinsicV2;
-  'Option<ExtrinsicV2>': Option<ExtrinsicV2>;
-  'Vec<ExtrinsicV2>': Vec<ExtrinsicV2>;
-  ExtrinsicV3: ExtrinsicV3;
-  'Option<ExtrinsicV3>': Option<ExtrinsicV3>;
-  'Vec<ExtrinsicV3>': Vec<ExtrinsicV3>;
-  ExtrinsicV4: ExtrinsicV4;
-  'Option<ExtrinsicV4>': Option<ExtrinsicV4>;
-  'Vec<ExtrinsicV4>': Vec<ExtrinsicV4>;
   Hash: Hash;
   'Option<Hash>': Option<Hash>;
   'Vec<Hash>': Vec<Hash>;
diff --git a/packages/types/src/interfaces/runtime/definitions.ts b/packages/types/src/interfaces/runtime/definitions.ts
index 3fef70a773..c5e39bc0ca 100644
--- a/packages/types/src/interfaces/runtime/definitions.ts
+++ b/packages/types/src/interfaces/runtime/definitions.ts
@@ -2,8 +2,30 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
+// Extrinsic definitions, extracted for readability
+const extrinsic = {
+  Extrinsic: 'GenericExtrinsic',
+  ExtrinsicEra: 'GenericExtrinsicEra',
+  ExtrinsicPayload: 'GenericExtrinsicPayload',
+  ExtrinsicV1: 'GenericExtrinsicV1',
+  ExtrinsicPayloadV1: 'GenericExtrinsicPayloadV1',
+  ExtrinsicSignatureV1: 'GenericExtrinsicSignatureV1',
+  ExtrinsicV2: 'GenericExtrinsicV2',
+  ExtrinsicPayloadV2: 'GenericExtrinsicPayloadV2',
+  ExtrinsicSignatureV2: 'GenericExtrinsicSignatureV2',
+  ExtrinsicV3: 'GenericExtrinsicV3',
+  ExtrinsicPayloadV3: 'GenericExtrinsicPayloadV3',
+  ExtrinsicSignatureV3: 'GenericExtrinsicSignatureV3',
+  ExtrinsicV4: 'GenericExtrinsicV4',
+  ExtrinsicPayloadV4: 'GenericExtrinsicPayloadV4',
+  ExtrinsicSignatureV4: 'GenericExtrinsicSignatureV4',
+  ExtrinsicUnknown: 'GenericExtrinsicUnknown',
+  ExtrinsicPayloadUnknown: 'GenericExtrinsicPayloadUnknown'
+};
+
 export default {
   types: {
+    ...extrinsic,
     AccountId: 'GenericAccountId',
     AccountIdOf: 'AccountId',
     AccountIndex: 'GenericAccountIndex',
@@ -33,19 +55,6 @@ export default {
       weight: 'Weight',
       class: 'DispatchClass'
     },
-    Extrinsic: 'GenericExtrinsic',
-    ExtrinsicEra: 'GenericExtrinsicEra',
-    ExtrinsicPayload: 'GenericExtrinsicPayload',
-    ExtrinsicPayloadUnknown: 'GenericExtrinsicPayloadUnknown',
-    ExtrinsicPayloadV1: 'GenericExtrinsicPayloadV1',
-    ExtrinsicPayloadV2: 'GenericExtrinsicPayloadV2',
-    ExtrinsicPayloadV3: 'GenericExtrinsicPayloadV3',
-    ExtrinsicPayloadV4: 'GenericExtrinsicPayloadV4',
-    ExtrinsicUnknown: 'GenericExtrinsicUnknown',
-    ExtrinsicV1: 'GenericExtrinsicV1',
-    ExtrinsicV2: 'GenericExtrinsicV2',
-    ExtrinsicV3: 'GenericExtrinsicV3',
-    ExtrinsicV4: 'GenericExtrinsicV4',
     Hash: 'H256',
     Header: {
       parentHash: 'Hash',
diff --git a/packages/types/src/interfaces/runtime/types.ts b/packages/types/src/interfaces/runtime/types.ts
index ee32bc2023..0cc05d46b8 100644
--- a/packages/types/src/interfaces/runtime/types.ts
+++ b/packages/types/src/interfaces/runtime/types.ts
@@ -3,7 +3,7 @@
 
 import { Codec, ITuple } from '@polkadot/types/types';
 import { Compact, Enum, Struct } from '@polkadot/types/codec';
-import { Bytes, Fixed64, GenericAccountId, GenericAccountIndex, GenericAddress, GenericBlock, GenericCall, GenericConsensusEngineId, GenericDigest, GenericDigestItem, GenericExtrinsic, GenericExtrinsicEra, GenericExtrinsicPayload, GenericExtrinsicPayloadUnknown, GenericExtrinsicPayloadV1, GenericExtrinsicPayloadV2, GenericExtrinsicPayloadV3, GenericExtrinsicPayloadV4, GenericExtrinsicUnknown, GenericExtrinsicV1, GenericExtrinsicV2, GenericExtrinsicV3, GenericExtrinsicV4, GenericImmortalEra, GenericMortalEra, GenericOrigin, GenericSignerPayload, H256, H512, Null, StorageData, StorageKey, bool, u128, u32, u64, u8 } from '@polkadot/types/primitive';
+import { Bytes, Fixed64, GenericAccountId, GenericAccountIndex, GenericAddress, GenericBlock, GenericCall, GenericConsensusEngineId, GenericDigest, GenericDigestItem, GenericExtrinsic, GenericExtrinsicEra, GenericExtrinsicPayload, GenericExtrinsicPayloadUnknown, GenericExtrinsicPayloadV1, GenericExtrinsicPayloadV2, GenericExtrinsicPayloadV3, GenericExtrinsicPayloadV4, GenericExtrinsicSignatureV1, GenericExtrinsicSignatureV2, GenericExtrinsicSignatureV3, GenericExtrinsicSignatureV4, GenericExtrinsicUnknown, GenericExtrinsicV1, GenericExtrinsicV2, GenericExtrinsicV3, GenericExtrinsicV4, GenericImmortalEra, GenericMortalEra, GenericOrigin, GenericSignerPayload, H256, H512, Null, StorageData, StorageKey, bool, u128, u32, u64, u8 } from '@polkadot/types/primitive';
 
 /** @name AccountId */
 export interface AccountId extends GenericAccountId {}
@@ -102,6 +102,18 @@ export interface ExtrinsicPayloadV3 extends GenericExtrinsicPayloadV3 {}
 /** @name ExtrinsicPayloadV4 */
 export interface ExtrinsicPayloadV4 extends GenericExtrinsicPayloadV4 {}
 
+/** @name ExtrinsicSignatureV1 */
+export interface ExtrinsicSignatureV1 extends GenericExtrinsicSignatureV1 {}
+
+/** @name ExtrinsicSignatureV2 */
+export interface ExtrinsicSignatureV2 extends GenericExtrinsicSignatureV2 {}
+
+/** @name ExtrinsicSignatureV3 */
+export interface ExtrinsicSignatureV3 extends GenericExtrinsicSignatureV3 {}
+
+/** @name ExtrinsicSignatureV4 */
+export interface ExtrinsicSignatureV4 extends GenericExtrinsicSignatureV4 {}
+
 /** @name ExtrinsicUnknown */
 export interface ExtrinsicUnknown extends GenericExtrinsicUnknown {}
 
diff --git a/packages/types/src/primitive/Bool.ts b/packages/types/src/primitive/Bool.ts
index 7c76fca611..4e13047ef3 100644
--- a/packages/types/src/primitive/Bool.ts
+++ b/packages/types/src/primitive/Bool.ts
@@ -25,6 +25,7 @@ export default class Bool extends Boolean implements Codec {
     this.registry = registry;
   }
 
+  /** @internal */
   private static decodeBool (value: any): boolean {
     if (value instanceof Boolean) {
       return value.valueOf();
diff --git a/packages/types/src/primitive/Bytes.ts b/packages/types/src/primitive/Bytes.ts
index ba8b3485fb..237b47e94a 100644
--- a/packages/types/src/primitive/Bytes.ts
+++ b/packages/types/src/primitive/Bytes.ts
@@ -21,6 +21,7 @@ export default class Bytes extends Raw {
     super(registry, Bytes.decodeBytes(value));
   }
 
+  /** @internal */
   private static decodeBytes (value?: AnyU8a): Uint8Array | undefined {
     if (Array.isArray(value) || isString(value)) {
       return u8aToU8a(value);
@@ -33,6 +34,7 @@ export default class Bytes extends Raw {
     return value;
   }
 
+  /** @internal */
   private static decodeBytesU8a (value: Uint8Array): Uint8Array {
     if (!value.length) {
       return new Uint8Array();
diff --git a/packages/types/src/primitive/Extrinsic/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/Extrinsic.ts
index 5c365cf2fc..c9501599a1 100644
--- a/packages/types/src/primitive/Extrinsic/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/Extrinsic.ts
@@ -39,7 +39,7 @@ const VERSIONS: InterfaceTypes[] = [
 export { TRANSACTION_VERSION as LATEST_EXTRINSIC_VERSION } from './v4/Extrinsic';
 
 /**
- * @name Extrinsic
+ * @name GenericExtrinsic
  * @description
  * Representation of an Extrinsic in the system. It contains the actual call,
  * (optional) signature and encodes with an actual length prefix
@@ -55,6 +55,7 @@ export default class Extrinsic extends Base<ExtrinsicVx | ExtrinsicUnknown> impl
     super(registry, Extrinsic.decodeExtrinsic(registry, value, version));
   }
 
+  /** @internal */
   private static newFromValue (registry: Registry, value: any, version: number): ExtrinsicVx | ExtrinsicUnknown {
     if (value instanceof Extrinsic) {
       return value.raw;
@@ -68,6 +69,7 @@ export default class Extrinsic extends Base<ExtrinsicVx | ExtrinsicUnknown> impl
     return createType(registry, type, value, { isSigned, version }) as ExtrinsicVx;
   }
 
+  /** @internal */
   public static decodeExtrinsic (registry: Registry, value: Extrinsic | ExtrinsicValue | AnyU8a | Call | undefined, version: number = DEFAULT_VERSION): ExtrinsicVx | ExtrinsicUnknown {
     if (Array.isArray(value) || isHex(value)) {
       return Extrinsic.decodeU8aLike(registry, value, version);
@@ -80,6 +82,7 @@ export default class Extrinsic extends Base<ExtrinsicVx | ExtrinsicUnknown> impl
     return Extrinsic.newFromValue(registry, value, version);
   }
 
+  /** @internal */
   private static decodeU8aLike (registry: Registry, value: string | number[], version: number): ExtrinsicVx | ExtrinsicUnknown {
     // Instead of the block below, it should simply be:
     // return Extrinsic.decodeExtrinsic(hexToU8a(value as string));
@@ -100,6 +103,7 @@ export default class Extrinsic extends Base<ExtrinsicVx | ExtrinsicUnknown> impl
     );
   }
 
+  /** @internal */
   private static decodeU8a (registry: Registry, value: Uint8Array, version: number): ExtrinsicVx | ExtrinsicUnknown {
     if (!value.length) {
       return Extrinsic.newFromValue(registry, new Uint8Array(), version);
diff --git a/packages/types/src/primitive/Extrinsic/ExtrinsicEra.ts b/packages/types/src/primitive/Extrinsic/ExtrinsicEra.ts
index 80dc3e5782..d5839a15e1 100644
--- a/packages/types/src/primitive/Extrinsic/ExtrinsicEra.ts
+++ b/packages/types/src/primitive/Extrinsic/ExtrinsicEra.ts
@@ -55,6 +55,7 @@ export class MortalEra extends Tuple {
     }, MortalEra.decodeMortalEra(registry, value));
   }
 
+  /** @internal */
   private static decodeMortalEra (registry: Registry, value?: MortalMethod | Uint8Array | number[] | string): MortalEraValue {
     if (isHex(value)) {
       return MortalEra.decodeMortalU8a(registry, hexToU8a(value));
@@ -71,6 +72,7 @@ export class MortalEra extends Tuple {
     throw new Error('Invalid data passed to Mortal era');
   }
 
+  /** @internal */
   private static decodeMortalObject (registry: Registry, value: MortalMethod): MortalEraValue {
     const { current, period } = value;
     let calPeriod = Math.pow(2, Math.ceil(Math.log2(period)));
@@ -82,6 +84,7 @@ export class MortalEra extends Tuple {
     return [new U64(registry, calPeriod), new U64(registry, quantizedPhase)];
   }
 
+  /** @internal */
   private static decodeMortalU8a (registry: Registry, value: Uint8Array): MortalEraValue {
     if (value.length === 0) {
       return [new U64(registry), new U64(registry)];
@@ -186,7 +189,7 @@ export class MortalEra extends Tuple {
 }
 
 /**
- * @name ExtrinsicEra
+ * @name GenericExtrinsicEra
  * @description
  * The era for an extrinsic, indicating either a mortal or immortal extrinsic
  */
@@ -198,6 +201,7 @@ export default class ExtrinsicEra extends Enum implements IExtrinsicEra {
     }, ExtrinsicEra.decodeExtrinsicEra(value));
   }
 
+  /** @internal */
   // eslint-disable-next-line @typescript-eslint/ban-types
   private static decodeExtrinsicEra (value: IExtrinsicEra | MortalMethod | MortalEnumDef | ImmortalEnumDef | Uint8Array | string = new Uint8Array()): Uint8Array | Object | undefined {
     if (!value) {
diff --git a/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.spec.ts b/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.spec.ts
index bc1cc4c2b6..adaf5c4578 100644
--- a/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.spec.ts
+++ b/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.spec.ts
@@ -1,4 +1,4 @@
-// Copyright 2017-2020 @polkadot/api authors & contributors
+// Copyright 2017-2020 @polkadot/types authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.ts b/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.ts
index 7ee26489ec..0f8cee9bb4 100644
--- a/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/ExtrinsicPayload.ts
@@ -31,7 +31,7 @@ const VERSIONS: InterfaceTypes[] = [
 ];
 
 /**
- * @name ExtrinsicPayload
+ * @name GenericExtrinsicPayload
  * @description
  * A signing payload for an [[Extrinsic]]. For the final encoding, it is variable length based
  * on the contents included
@@ -41,6 +41,7 @@ export default class ExtrinsicPayload extends Base<ExtrinsicPayloadVx> {
     super(registry, ExtrinsicPayload.decodeExtrinsicPayload(registry, value as ExtrinsicPayloadValue, version));
   }
 
+  /** @internal */
   public static decodeExtrinsicPayload (registry: Registry, value: ExtrinsicPayload | ExtrinsicPayloadValue | Uint8Array | string | undefined, version: number = DEFAULT_VERSION): ExtrinsicPayloadVx {
     if (value instanceof ExtrinsicPayload) {
       return value.raw;
diff --git a/packages/types/src/primitive/Extrinsic/ExtrinsicPayloadUnknown.ts b/packages/types/src/primitive/Extrinsic/ExtrinsicPayloadUnknown.ts
index 19fa7bfdbb..5b4d22616e 100644
--- a/packages/types/src/primitive/Extrinsic/ExtrinsicPayloadUnknown.ts
+++ b/packages/types/src/primitive/Extrinsic/ExtrinsicPayloadUnknown.ts
@@ -8,7 +8,7 @@ import { ExtrinsicPayloadOptions } from './types';
 import Struct from '../../codec/Struct';
 
 /**
- * @name ExtrinsicPayloadUnknown
+ * @name GenericExtrinsicPayloadUnknown
  * @description
  * A default handler for payloads where the version is not known (default throw)
  */
diff --git a/packages/types/src/primitive/Extrinsic/ExtrinsicUnknown.ts b/packages/types/src/primitive/Extrinsic/ExtrinsicUnknown.ts
index cb50670d32..ef10fdddd2 100644
--- a/packages/types/src/primitive/Extrinsic/ExtrinsicUnknown.ts
+++ b/packages/types/src/primitive/Extrinsic/ExtrinsicUnknown.ts
@@ -9,7 +9,7 @@ import Struct from '../../codec/Struct';
 import { UNMASK_VERSION } from './constants';
 
 /**
- * @name ExtrinsicUnknown
+ * @name GenericExtrinsicUnknown
  * @description
  * A default handler for extrinsics where the version is not known (default throw)
  */
diff --git a/packages/types/src/primitive/Extrinsic/SignedExtensions.ts b/packages/types/src/primitive/Extrinsic/SignedExtensions.ts
new file mode 100644
index 0000000000..e7ffdbd2ee
--- /dev/null
+++ b/packages/types/src/primitive/Extrinsic/SignedExtensions.ts
@@ -0,0 +1,86 @@
+// Copyright 2017-2020 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+import { InterfaceTypes } from '../../types';
+
+type ExtTypes = Record<string, InterfaceTypes>;
+type ExtInfo = {
+  extra: ExtTypes;
+  types: ExtTypes;
+}
+
+// A mapping of the known signed extensions to the extra fields that they contain. Unlike in the actual extensions,
+// we define the extra fields not as a Tuple, but rather as a struct so they can be named. These will be expanded
+// into the various fields when added to the payload (we only support V4 onwards with these, V3 and earlier are
+// deemded fixed and non-changeable)
+const allExtensions: Record<string, ExtInfo> = {
+  ChargeTransactionPayment: {
+    extra: {},
+    types: {
+      tip: 'Compact<Balance>'
+    }
+  },
+  CheckBlockGasLimit: {
+    extra: {},
+    types: {}
+  },
+  CheckEra: {
+    extra: {
+      blockHash: 'Hash'
+    },
+    types: {
+      era: 'ExtrinsicEra'
+    }
+  },
+  CheckGenesis: {
+    extra: {
+      genesisHash: 'Hash'
+    },
+    types: {}
+  },
+  CheckNonce: {
+    extra: {},
+    types: {
+      nonce: 'Compact<Index>'
+    }
+  },
+  CheckVersion: {
+    extra: {
+      specVersion: 'u32'
+    },
+    types: {}
+  },
+  CheckWeight: {
+    extra: {},
+    types: {}
+  }
+};
+
+// the v4 signed extensions (the order is important here)
+const defaultExtensions: Array<keyof typeof allExtensions> = [
+  'CheckVersion',
+  'CheckGenesis',
+  'CheckEra',
+  'CheckNonce',
+  'CheckWeight',
+  'ChargeTransactionPayment',
+  'CheckBlockGasLimit'
+];
+
+function expandExtensionTypes (extensions: string[], type: keyof ExtInfo): ExtTypes {
+  return extensions
+    .map((key): ExtInfo => {
+      const info = allExtensions[key];
+
+      if (!info) {
+        console.warn(`Unknown signed extension ${key} found, treating it as empty with no extra data`);
+      }
+
+      return info;
+    })
+    .filter((info): boolean => !!info)
+    .reduce((result, info): ExtTypes => ({ ...result, ...info[type] }), {});
+}
+
+export { allExtensions, defaultExtensions, expandExtensionTypes };
diff --git a/packages/types/src/primitive/Extrinsic/SignerPayload.spec.ts b/packages/types/src/primitive/Extrinsic/SignerPayload.spec.ts
index 342124ab53..0d05d49229 100644
--- a/packages/types/src/primitive/Extrinsic/SignerPayload.spec.ts
+++ b/packages/types/src/primitive/Extrinsic/SignerPayload.spec.ts
@@ -1,4 +1,4 @@
-// Copyright 2017-2020 @polkadot/api authors & contributors
+// Copyright 2017-2020 @polkadot/types authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
diff --git a/packages/types/src/primitive/Extrinsic/SignerPayload.ts b/packages/types/src/primitive/Extrinsic/SignerPayload.ts
index 24af5199a0..b64606b6b9 100644
--- a/packages/types/src/primitive/Extrinsic/SignerPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/SignerPayload.ts
@@ -1,4 +1,4 @@
-// Copyright 2017-2020 @polkadot/api authors & contributors
+// Copyright 2017-2020 @polkadot/types authors & contributors
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
@@ -38,6 +38,11 @@ const _Payload: Constructor<SignerPayloadType> = Struct.with({
   version: 'u8'
 }) as any;
 
+/**
+ * @name SignerPayload
+ * @description
+ * A generic signer payload that can be used for serialization between API and signer
+ */
 export default class SignerPayload extends _Payload implements ISignerPayload {
   /**
    * @description Creates an representation of the structure as an ISignerPayload JSON
diff --git a/packages/types/src/primitive/Extrinsic/index.ts b/packages/types/src/primitive/Extrinsic/index.ts
index bd0dd06cde..e3ea192f97 100644
--- a/packages/types/src/primitive/Extrinsic/index.ts
+++ b/packages/types/src/primitive/Extrinsic/index.ts
@@ -2,7 +2,6 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-// generic
 export { default as GenericExtrinsic } from './Extrinsic';
 export { default as GenericExtrinsicEra, MortalEra as GenericMortalEra, ImmortalEra as GenericImmortalEra } from './ExtrinsicEra';
 export { default as GenericExtrinsicPayload } from './ExtrinsicPayload';
@@ -10,15 +9,7 @@ export { default as GenericExtrinsicPayloadUnknown } from './ExtrinsicPayloadUnk
 export { default as GenericExtrinsicUnknown } from './ExtrinsicUnknown';
 export { default as GenericSignerPayload } from './SignerPayload';
 
-// versioned
-export { default as GenericExtrinsicV1 } from './v1/Extrinsic';
-export { default as GenericExtrinsicPayloadV1 } from './v1/ExtrinsicPayload';
-
-export { default as GenericExtrinsicV2 } from './v2/Extrinsic';
-export { default as GenericExtrinsicPayloadV2 } from './v2/ExtrinsicPayload';
-
-export { default as GenericExtrinsicV3 } from './v3/Extrinsic';
-export { default as GenericExtrinsicPayloadV3 } from './v3/ExtrinsicPayload';
-
-export { default as GenericExtrinsicV4 } from './v4/Extrinsic';
-export { default as GenericExtrinsicPayloadV4 } from './v4/ExtrinsicPayload';
+export * from './v1';
+export * from './v2';
+export * from './v3';
+export * from './v4';
diff --git a/packages/types/src/primitive/Extrinsic/v1/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/v1/Extrinsic.ts
index cae0b7b644..fe612a7b22 100644
--- a/packages/types/src/primitive/Extrinsic/v1/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/v1/Extrinsic.ts
@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Address, Call } from '../../../interfaces/runtime';
+import { Address, Call, ExtrinsicSignatureV1 } from '../../../interfaces/runtime';
 import { ExtrinsicPayloadValue, IExtrinsicImpl, IKeyringPair, Registry, SignatureOptions } from '../../../types';
 import { ExtrinsicOptions } from '../types';
 
@@ -10,7 +10,6 @@ import { isU8a } from '@polkadot/util';
 
 import { createType } from '../../../codec/create';
 import Struct from '../../../codec/Struct';
-import ExtrinsicSignatureV1 from './ExtrinsicSignature';
 
 export interface ExtrinsicValueV1 {
   method?: Call;
@@ -20,26 +19,25 @@ export interface ExtrinsicValueV1 {
 const TRANSACTION_VERSION = 1;
 
 /**
- * @name ExtrinsicV1
+ * @name GenericExtrinsicV1
  * @description
  * The first generation of compact extrinsics
  */
 export default class ExtrinsicV1 extends Struct implements IExtrinsicImpl {
   constructor (registry: Registry, value?: Uint8Array | ExtrinsicValueV1, { isSigned }: Partial<ExtrinsicOptions> = {}) {
     super(registry, {
-      signature: ExtrinsicSignatureV1,
+      signature: 'ExtrinsicSignatureV1',
       method: 'Call'
     }, ExtrinsicV1.decodeExtrinsic(registry, value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsic (registry: Registry, value?: Uint8Array | ExtrinsicValueV1, isSigned = false): ExtrinsicValueV1 {
-    if (!value) {
-      return {};
-    } else if (value instanceof ExtrinsicV1) {
+    if (value instanceof ExtrinsicV1) {
       return value;
     } else if (isU8a(value)) {
       // here we decode manually since we need to pull through the version information
-      const signature = new ExtrinsicSignatureV1(registry, value, { isSigned });
+      const signature = createType(registry, 'ExtrinsicSignatureV1', value, { isSigned });
       const method = createType(registry, 'Call', value.subarray(signature.encodedLength));
 
       return {
@@ -48,7 +46,7 @@ export default class ExtrinsicV1 extends Struct implements IExtrinsicImpl {
       };
     }
 
-    return value;
+    return value || {};
   }
 
   /**
diff --git a/packages/types/src/primitive/Extrinsic/v1/ExtrinsicPayload.ts b/packages/types/src/primitive/Extrinsic/v1/ExtrinsicPayload.ts
index 794021d548..12736db268 100644
--- a/packages/types/src/primitive/Extrinsic/v1/ExtrinsicPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/v1/ExtrinsicPayload.ts
@@ -11,7 +11,7 @@ import Bytes from '../../../primitive/Bytes';
 import { sign } from '../util';
 
 /**
- * @name ExtrinsicPayloadV1
+ * @name GenericExtrinsicPayloadV1
  * @description
  * A signing payload for an [[Extrinsic]]. For the final encoding, it is variable length based
  * on the contents included
diff --git a/packages/types/src/primitive/Extrinsic/v1/ExtrinsicSignature.ts b/packages/types/src/primitive/Extrinsic/v1/ExtrinsicSignature.ts
index 9f1686f2d3..32eac24d80 100644
--- a/packages/types/src/primitive/Extrinsic/v1/ExtrinsicSignature.ts
+++ b/packages/types/src/primitive/Extrinsic/v1/ExtrinsicSignature.ts
@@ -13,7 +13,7 @@ import { EMPTY_U8A, IMMORTAL_ERA } from '../constants';
 import ExtrinsicPayloadV1 from './ExtrinsicPayload';
 
 /**
- * @name ExtrinsicSignatureV1
+ * @name GenericExtrinsicSignatureV1
  * @description
  * A container for the [[Signature]] associated with a specific [[Extrinsic]]
  */
@@ -32,6 +32,7 @@ export default class ExtrinsicSignatureV1 extends Struct implements IExtrinsicSi
     }, ExtrinsicSignatureV1.decodeExtrinsicSignature(value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsicSignature (value: ExtrinsicSignatureV1 | Uint8Array | undefined, isSigned = false): ExtrinsicSignatureV1 | Uint8Array {
     if (!value) {
       return EMPTY_U8A;
diff --git a/packages/types/src/primitive/Extrinsic/v1/index.ts b/packages/types/src/primitive/Extrinsic/v1/index.ts
new file mode 100644
index 0000000000..d020f4aa93
--- /dev/null
+++ b/packages/types/src/primitive/Extrinsic/v1/index.ts
@@ -0,0 +1,7 @@
+// Copyright 2017-2020 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as GenericExtrinsicV1 } from './Extrinsic';
+export { default as GenericExtrinsicPayloadV1 } from './ExtrinsicPayload';
+export { default as GenericExtrinsicSignatureV1 } from './ExtrinsicSignature';
diff --git a/packages/types/src/primitive/Extrinsic/v2/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/v2/Extrinsic.ts
index 61e8fd4cc7..801b2ce669 100644
--- a/packages/types/src/primitive/Extrinsic/v2/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/v2/Extrinsic.ts
@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Address, Call } from '../../../interfaces/runtime';
+import { Address, Call, ExtrinsicSignatureV2 } from '../../../interfaces/runtime';
 import { ExtrinsicPayloadValue, IExtrinsicImpl, IKeyringPair, Registry, SignatureOptions } from '../../../types';
 import { ExtrinsicOptions } from '../types';
 
@@ -10,7 +10,6 @@ import { isU8a } from '@polkadot/util';
 
 import { createType, ClassOf } from '../../../codec/create';
 import Struct from '../../../codec/Struct';
-import ExtrinsicSignatureV2 from './ExtrinsicSignature';
 
 const TRANSACTION_VERSION = 2;
 
@@ -20,28 +19,27 @@ export interface ExtrinsicValueV2 {
 }
 
 /**
- * @name ExtrinsicV2
+ * @name GenericExtrinsicV2
  * @description
  * The second generation of compact extrinsics
  */
 export default class ExtrinsicV2 extends Struct implements IExtrinsicImpl {
   constructor (registry: Registry, value?: Uint8Array | ExtrinsicValueV2 | Call, { isSigned }: Partial<ExtrinsicOptions> = {}) {
     super(registry, {
-      signature: ExtrinsicSignatureV2,
+      signature: 'ExtrinsicSignatureV2',
       method: 'Call'
     }, ExtrinsicV2.decodeExtrinsic(registry, value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsic (registry: Registry, value?: Call | Uint8Array | ExtrinsicValueV2, isSigned = false): ExtrinsicValueV2 {
-    if (!value) {
-      return {};
-    } else if (value instanceof ExtrinsicV2) {
+    if (value instanceof ExtrinsicV2) {
       return value;
     } else if (value instanceof ClassOf(registry, 'Call')) {
       return { method: value };
     } else if (isU8a(value)) {
       // here we decode manually since we need to pull through the version information
-      const signature = new ExtrinsicSignatureV2(registry, value, { isSigned });
+      const signature = createType(registry, 'ExtrinsicSignatureV2', value, { isSigned });
       const method = createType(registry, 'Call', value.subarray(signature.encodedLength));
 
       return {
@@ -50,7 +48,7 @@ export default class ExtrinsicV2 extends Struct implements IExtrinsicImpl {
       };
     }
 
-    return value;
+    return value || {};
   }
 
   /**
diff --git a/packages/types/src/primitive/Extrinsic/v2/ExtrinsicPayload.ts b/packages/types/src/primitive/Extrinsic/v2/ExtrinsicPayload.ts
index d9d8cf14f2..488eaea6f9 100644
--- a/packages/types/src/primitive/Extrinsic/v2/ExtrinsicPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/v2/ExtrinsicPayload.ts
@@ -3,23 +3,15 @@
 // of the Apache-2.0 license. See the LICENSE file for details.
 
 import { Balance, ExtrinsicEra, Hash, Index } from '../../../interfaces/runtime';
-import { ExtrinsicPayloadValue, IKeyringPair, InterfaceTypes, Registry } from '../../../types';
+import { ExtrinsicPayloadValue, IKeyringPair, Registry } from '../../../types';
 
 import Compact from '../../../codec/Compact';
 import Struct from '../../../codec/Struct';
 import Bytes from '../../../primitive/Bytes';
 import { sign } from '../util';
 
-// the base definition (excluding extras)
-export const SignedPayloadBaseV2: Record<string, InterfaceTypes> = {
-  method: 'Bytes',
-  era: 'ExtrinsicEra',
-  nonce: 'Compact<Index>',
-  tip: 'Compact<Balance>'
-};
-
 /**
- * @name ExtrinsicPayloadV2
+ * @name GenericExtrinsicPayloadV2
  * @description
  * A signing payload for an [[Extrinsic]]. For the final encoding, it is variable length based
  * on the contents included
@@ -27,7 +19,10 @@ export const SignedPayloadBaseV2: Record<string, InterfaceTypes> = {
 export default class ExtrinsicPayloadV2 extends Struct {
   constructor (registry: Registry, value?: ExtrinsicPayloadValue | Uint8Array | string) {
     super(registry, {
-      ...SignedPayloadBaseV2,
+      method: 'Bytes',
+      era: 'ExtrinsicEra',
+      nonce: 'Compact<Index>',
+      tip: 'Compact<Balance>',
       blockHash: 'Hash'
     }, value);
   }
diff --git a/packages/types/src/primitive/Extrinsic/v2/ExtrinsicSignature.ts b/packages/types/src/primitive/Extrinsic/v2/ExtrinsicSignature.ts
index 265459c94b..ba398252a7 100644
--- a/packages/types/src/primitive/Extrinsic/v2/ExtrinsicSignature.ts
+++ b/packages/types/src/primitive/Extrinsic/v2/ExtrinsicSignature.ts
@@ -13,7 +13,7 @@ import { EMPTY_U8A, IMMORTAL_ERA } from '../constants';
 import ExtrinsicPayloadV2 from './ExtrinsicPayload';
 
 /**
- * @name ExtrinsicSignatureV2
+ * @name GenericExtrinsicSignatureV2
  * @description
  * A container for the [[Signature]] associated with a specific [[Extrinsic]]
  */
@@ -28,6 +28,7 @@ export default class ExtrinsicSignatureV2 extends Struct implements IExtrinsicSi
     }, ExtrinsicSignatureV2.decodeExtrinsicSignature(value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsicSignature (value: ExtrinsicSignatureV2 | Uint8Array | undefined, isSigned = false): ExtrinsicSignatureV2 | Uint8Array {
     if (!value) {
       return EMPTY_U8A;
diff --git a/packages/types/src/primitive/Extrinsic/v2/index.ts b/packages/types/src/primitive/Extrinsic/v2/index.ts
new file mode 100644
index 0000000000..f5f90d1ccf
--- /dev/null
+++ b/packages/types/src/primitive/Extrinsic/v2/index.ts
@@ -0,0 +1,7 @@
+// Copyright 2017-2020 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as GenericExtrinsicV2 } from './Extrinsic';
+export { default as GenericExtrinsicPayloadV2 } from './ExtrinsicPayload';
+export { default as GenericExtrinsicSignatureV2 } from './ExtrinsicSignature';
diff --git a/packages/types/src/primitive/Extrinsic/v3/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/v3/Extrinsic.ts
index ef16d4ecf4..00253c2e9d 100644
--- a/packages/types/src/primitive/Extrinsic/v3/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/v3/Extrinsic.ts
@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Address, Call } from '../../../interfaces/runtime';
+import { Address, Call, ExtrinsicSignatureV3 } from '../../../interfaces/runtime';
 import { ExtrinsicPayloadValue, IExtrinsicImpl, IKeyringPair, Registry, SignatureOptions } from '../../../types';
 import { ExtrinsicOptions } from '../types';
 
@@ -10,7 +10,6 @@ import { isU8a } from '@polkadot/util';
 
 import { createType, ClassOf } from '../../../codec/create';
 import Struct from '../../../codec/Struct';
-import ExtrinsicSignatureV3 from './ExtrinsicSignature';
 
 const TRANSACTION_VERSION = 3;
 
@@ -20,28 +19,27 @@ export interface ExtrinsicValueV3 {
 }
 
 /**
- * @name ExtrinsicV3
+ * @name GenericExtrinsicV3
  * @description
  * The third generation of compact extrinsics
  */
 export default class ExtrinsicV3 extends Struct implements IExtrinsicImpl {
   constructor (registry: Registry, value?: Uint8Array | ExtrinsicValueV3 | Call, { isSigned }: Partial<ExtrinsicOptions> = {}) {
     super(registry, {
-      signature: ExtrinsicSignatureV3,
+      signature: 'ExtrinsicSignatureV3',
       method: 'Call'
     }, ExtrinsicV3.decodeExtrinsic(registry, value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsic (registry: Registry, value?: Call | Uint8Array | ExtrinsicValueV3, isSigned = false): ExtrinsicValueV3 {
-    if (!value) {
-      return {};
-    } else if (value instanceof ExtrinsicV3) {
+    if (value instanceof ExtrinsicV3) {
       return value;
     } else if (value instanceof ClassOf(registry, 'Call')) {
       return { method: value };
     } else if (isU8a(value)) {
       // here we decode manually since we need to pull through the version information
-      const signature = new ExtrinsicSignatureV3(registry, value, { isSigned });
+      const signature = createType(registry, 'ExtrinsicSignatureV3', value, { isSigned });
       const method = createType(registry, 'Call', value.subarray(signature.encodedLength));
 
       return {
@@ -50,7 +48,7 @@ export default class ExtrinsicV3 extends Struct implements IExtrinsicImpl {
       };
     }
 
-    return value;
+    return value || {};
   }
 
   /**
diff --git a/packages/types/src/primitive/Extrinsic/v3/ExtrinsicPayload.ts b/packages/types/src/primitive/Extrinsic/v3/ExtrinsicPayload.ts
index 09aa55e765..4cd4dd2604 100644
--- a/packages/types/src/primitive/Extrinsic/v3/ExtrinsicPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/v3/ExtrinsicPayload.ts
@@ -10,10 +10,9 @@ import Struct from '../../../codec/Struct';
 import Bytes from '../../../primitive/Bytes';
 import u32 from '../../../primitive/U32';
 import { sign } from '../util';
-import { SignedPayloadBaseV2 as SignedPayloadBaseV3 } from '../v2/ExtrinsicPayload';
 
 /**
- * @name ExtrinsicPayloadV3
+ * @name GenericExtrinsicPayloadV3
  * @description
  * A signing payload for an [[Extrinsic]]. For the final encoding, it is variable length based
  * on the contents included
@@ -21,8 +20,12 @@ import { SignedPayloadBaseV2 as SignedPayloadBaseV3 } from '../v2/ExtrinsicPaylo
 export default class ExtrinsicPayloadV3 extends Struct {
   constructor (registry: Registry, value?: ExtrinsicPayloadValue | Uint8Array | string) {
     super(registry, {
-      ...SignedPayloadBaseV3,
-      // signed extensions
+      method: 'Bytes',
+      // extensions
+      era: 'ExtrinsicEra',
+      nonce: 'Compact<Index>',
+      tip: 'Compact<Balance>',
+      // extensions (additional)
       specVersion: 'u32',
       genesisHash: 'Hash',
       blockHash: 'Hash'
diff --git a/packages/types/src/primitive/Extrinsic/v3/ExtrinsicSignature.ts b/packages/types/src/primitive/Extrinsic/v3/ExtrinsicSignature.ts
index 6f9f965f1c..539856a978 100644
--- a/packages/types/src/primitive/Extrinsic/v3/ExtrinsicSignature.ts
+++ b/packages/types/src/primitive/Extrinsic/v3/ExtrinsicSignature.ts
@@ -11,7 +11,7 @@ import ExtrinsicSignatureV2 from '../v2/ExtrinsicSignature';
 import ExtrinsicPayloadV3 from './ExtrinsicPayload';
 
 /**
- * @name ExtrinsicSignatureV3
+ * @name GenericExtrinsicSignatureV3
  * @description
  * A container for the [[Signature]] associated with a specific [[Extrinsic]]
  */
diff --git a/packages/types/src/primitive/Extrinsic/v3/index.ts b/packages/types/src/primitive/Extrinsic/v3/index.ts
new file mode 100644
index 0000000000..935ffcd8bd
--- /dev/null
+++ b/packages/types/src/primitive/Extrinsic/v3/index.ts
@@ -0,0 +1,7 @@
+// Copyright 2017-2020 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as GenericExtrinsicV3 } from './Extrinsic';
+export { default as GenericExtrinsicPayloadV3 } from './ExtrinsicPayload';
+export { default as GenericExtrinsicSignatureV3 } from './ExtrinsicSignature';
diff --git a/packages/types/src/primitive/Extrinsic/v4/Extrinsic.ts b/packages/types/src/primitive/Extrinsic/v4/Extrinsic.ts
index f967edacb1..41464d4eab 100644
--- a/packages/types/src/primitive/Extrinsic/v4/Extrinsic.ts
+++ b/packages/types/src/primitive/Extrinsic/v4/Extrinsic.ts
@@ -2,7 +2,7 @@
 // This software may be modified and distributed under the terms
 // of the Apache-2.0 license. See the LICENSE file for details.
 
-import { Address, Call } from '../../../interfaces/runtime';
+import { Address, Call, ExtrinsicSignatureV4 } from '../../../interfaces/runtime';
 import { ExtrinsicPayloadValue, IExtrinsicImpl, IKeyringPair, Registry, SignatureOptions } from '../../../types';
 import { ExtrinsicOptions } from '../types';
 
@@ -10,7 +10,6 @@ import { isU8a } from '@polkadot/util';
 
 import { createType, ClassOf } from '../../../codec/create';
 import Struct from '../../../codec/Struct';
-import ExtrinsicSignatureV4 from './ExtrinsicSignature';
 
 export const TRANSACTION_VERSION = 4;
 
@@ -20,28 +19,27 @@ export interface ExtrinsicValueV4 {
 }
 
 /**
- * @name ExtrinsicV4
+ * @name GenericExtrinsicV4
  * @description
  * The third generation of compact extrinsics
  */
 export default class ExtrinsicV4 extends Struct implements IExtrinsicImpl {
   constructor (registry: Registry, value?: Uint8Array | ExtrinsicValueV4 | Call, { isSigned }: Partial<ExtrinsicOptions> = {}) {
     super(registry, {
-      signature: ExtrinsicSignatureV4,
+      signature: 'ExtrinsicSignatureV4',
       method: 'Call'
     }, ExtrinsicV4.decodeExtrinsic(registry, value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsic (registry: Registry, value?: Call | Uint8Array | ExtrinsicValueV4, isSigned = false): ExtrinsicValueV4 {
-    if (!value) {
-      return {};
-    } else if (value instanceof ExtrinsicV4) {
+    if (value instanceof ExtrinsicV4) {
       return value;
     } else if (value instanceof ClassOf(registry, 'Call')) {
       return { method: value };
     } else if (isU8a(value)) {
       // here we decode manually since we need to pull through the version information
-      const signature = new ExtrinsicSignatureV4(registry, value, { isSigned });
+      const signature = createType(registry, 'ExtrinsicSignatureV4', value, { isSigned });
       const method = createType(registry, 'Call', value.subarray(signature.encodedLength));
 
       return {
@@ -50,7 +48,7 @@ export default class ExtrinsicV4 extends Struct implements IExtrinsicImpl {
       };
     }
 
-    return value;
+    return value || {};
   }
 
   /**
diff --git a/packages/types/src/primitive/Extrinsic/v4/ExtrinsicPayload.ts b/packages/types/src/primitive/Extrinsic/v4/ExtrinsicPayload.ts
index 590239ac9a..3c95382a99 100644
--- a/packages/types/src/primitive/Extrinsic/v4/ExtrinsicPayload.ts
+++ b/packages/types/src/primitive/Extrinsic/v4/ExtrinsicPayload.ts
@@ -10,10 +10,9 @@ import Struct from '../../../codec/Struct';
 import Bytes from '../../../primitive/Bytes';
 import u32 from '../../../primitive/U32';
 import { sign } from '../util';
-import { SignedPayloadBaseV2 as SignedPayloadBaseV4 } from '../v2/ExtrinsicPayload';
 
 /**
- * @name ExtrinsicPayloadV4
+ * @name GenericExtrinsicPayloadV4
  * @description
  * A signing payload for an [[Extrinsic]]. For the final encoding, it is variable length based
  * on the contents included
@@ -21,19 +20,9 @@ import { SignedPayloadBaseV2 as SignedPayloadBaseV4 } from '../v2/ExtrinsicPaylo
 export default class ExtrinsicPayloadV4 extends Struct {
   constructor (registry: Registry, value?: ExtrinsicPayloadValue | Uint8Array | string) {
     super(registry, {
-      ...SignedPayloadBaseV4,
-      // TODO get the signed extensions from the registry and apply
-      ...{
-        // system::CheckVersion<Runtime>
-        specVersion: 'u32',
-        // system::CheckGenesis<Runtime>
-        genesisHash: 'Hash',
-        // system::CheckEra<Runtime>
-        blockHash: 'Hash'
-        // system::CheckNonce<Runtime>
-        // system::CheckWeight<Runtime>
-        // balances::TakeFees<Runtime>
-      }
+      method: 'Bytes',
+      ...registry.getSignedExtensionTypes(),
+      ...registry.getSignedExtensionExtra()
     }, value);
   }
 
diff --git a/packages/types/src/primitive/Extrinsic/v4/ExtrinsicSignature.ts b/packages/types/src/primitive/Extrinsic/v4/ExtrinsicSignature.ts
index f0df79cada..363d0d39a2 100644
--- a/packages/types/src/primitive/Extrinsic/v4/ExtrinsicSignature.ts
+++ b/packages/types/src/primitive/Extrinsic/v4/ExtrinsicSignature.ts
@@ -15,7 +15,7 @@ import { EMPTY_U8A, IMMORTAL_ERA } from '../constants';
 import ExtrinsicPayloadV4 from './ExtrinsicPayload';
 
 /**
- * @name ExtrinsicSignatureV4
+ * @name GenericExtrinsicSignatureV4
  * @description
  * A container for the [[Signature]] associated with a specific [[Extrinsic]]
  */
@@ -24,12 +24,11 @@ export default class ExtrinsicSignatureV4 extends Struct implements IExtrinsicSi
     super(registry, {
       signer: 'Address',
       signature: 'MultiSignature',
-      era: 'ExtrinsicEra',
-      nonce: 'Compact<Index>',
-      tip: 'Compact<Balance>'
+      ...registry.getSignedExtensionTypes()
     }, ExtrinsicSignatureV4.decodeExtrinsicSignature(value, isSigned));
   }
 
+  /** @internal */
   public static decodeExtrinsicSignature (value: ExtrinsicSignatureV4 | Uint8Array | undefined, isSigned = false): ExtrinsicSignatureV4 | Uint8Array {
     if (!value) {
       return EMPTY_U8A;
diff --git a/packages/types/src/primitive/Extrinsic/v4/index.ts b/packages/types/src/primitive/Extrinsic/v4/index.ts
new file mode 100644
index 0000000000..7bf857af07
--- /dev/null
+++ b/packages/types/src/primitive/Extrinsic/v4/index.ts
@@ -0,0 +1,7 @@
+// Copyright 2017-2020 @polkadot/types authors & contributors
+// This software may be modified and distributed under the terms
+// of the Apache-2.0 license. See the LICENSE file for details.
+
+export { default as GenericExtrinsicV4 } from './Extrinsic';
+export { default as GenericExtrinsicPayloadV4 } from './ExtrinsicPayload';
+export { default as GenericExtrinsicSignatureV4 } from './ExtrinsicSignature';
diff --git a/packages/types/src/primitive/Generic/AccountId.ts b/packages/types/src/primitive/Generic/AccountId.ts
index 93c738a016..f0535f54af 100644
--- a/packages/types/src/primitive/Generic/AccountId.ts
+++ b/packages/types/src/primitive/Generic/AccountId.ts
@@ -25,6 +25,7 @@ export default class AccountId extends U8aFixed {
     return encodeAddress(value);
   }
 
+  /** @internal */
   private static decodeAccountId (value: AnyU8a | AnyString): Uint8Array {
     if (isU8a(value) || Array.isArray(value)) {
       return u8aToU8a(value);
diff --git a/packages/types/src/primitive/Generic/AccountIndex.ts b/packages/types/src/primitive/Generic/AccountIndex.ts
index 0eae84cc0f..e49448102b 100644
--- a/packages/types/src/primitive/Generic/AccountIndex.ts
+++ b/packages/types/src/primitive/Generic/AccountIndex.ts
@@ -32,6 +32,7 @@ export default class AccountIndex extends U32 {
     super(registry, AccountIndex.decodeAccountIndex(value));
   }
 
+  /** @internal */
   public static decodeAccountIndex (value: AnyNumber): BN | Uint8Array | number | string {
     if (value instanceof AccountIndex) {
       // `value.toBn()` on AccountIndex returns a pure BN (i.e. not an
diff --git a/packages/types/src/primitive/Generic/Address.ts b/packages/types/src/primitive/Generic/Address.ts
index 779d768dfa..1467c02ec8 100644
--- a/packages/types/src/primitive/Generic/Address.ts
+++ b/packages/types/src/primitive/Generic/Address.ts
@@ -30,6 +30,7 @@ export default class Address extends Base<AccountId | AccountIndex> {
     super(registry, Address.decodeAddress(registry, value));
   }
 
+  /** @internal */
   public static decodeAddress (registry: Registry, value: AnyAddress): AccountId | AccountIndex {
     if (value instanceof AccountId || value instanceof AccountIndex) {
       return value;
@@ -44,6 +45,7 @@ export default class Address extends Base<AccountId | AccountIndex> {
     return Address.decodeString(registry, value);
   }
 
+  /** @internal */
   private static decodeString (registry: Registry, value: string): AccountId | AccountIndex {
     const decoded = decodeAddress(value);
 
@@ -52,6 +54,7 @@ export default class Address extends Base<AccountId | AccountIndex> {
       : createType(registry, 'AccountIndex', u8aToBn(decoded, true));
   }
 
+  /** @internal */
   private static decodeU8a (registry: Registry, value: Uint8Array): AccountId | AccountIndex {
     // This allows us to instantiate an address with a raw publicKey. Do this first before
     // we checking the first byte, otherwise we may split an already-existent valid address
diff --git a/packages/types/src/primitive/Generic/Call.ts b/packages/types/src/primitive/Generic/Call.ts
index 2596eb9dfc..9fb6748b52 100644
--- a/packages/types/src/primitive/Generic/Call.ts
+++ b/packages/types/src/primitive/Generic/Call.ts
@@ -61,6 +61,7 @@ export default class Call extends Struct implements IMethod {
    * - {@see DecodeMethodInput}
    * @param _meta - Metadata to use, so that `injectMethods` lookup is not
    * necessary.
+   * @internal
    */
   private static decodeCall (registry: Registry, value: DecodedMethod | Uint8Array | string = new Uint8Array(), _meta?: FunctionMetadataLatest): DecodedMethod {
     if (isHex(value) || isU8a(value)) {
@@ -72,6 +73,7 @@ export default class Call extends Struct implements IMethod {
     throw new Error(`Call: Cannot decode value '${value}' of type ${typeof value}`);
   }
 
+  /** @internal */
   private static decodeCallViaObject (registry: Registry, value: DecodedMethod, _meta?: FunctionMetadataLatest): DecodedMethod {
     // we only pass args/methodsIndex out
     const { args, callIndex } = value;
@@ -92,6 +94,7 @@ export default class Call extends Struct implements IMethod {
     };
   }
 
+  /** @internal */
   private static decodeCallViaU8a (registry: Registry, value: Uint8Array, _meta?: FunctionMetadataLatest): DecodedMethod {
     // We need 2 bytes for the callIndex
     const callIndex = new Uint8Array(2);
@@ -124,6 +127,7 @@ export default class Call extends Struct implements IMethod {
    * its metadata.
    *
    * @param meta - The function metadata used to get the definition.
+   * @internal
    */
   private static getArgsDef (registry: Registry, meta: FunctionMetadataLatest): ArgsDef {
     return Call.filterOrigin(meta).reduce((result, { name, type }): ArgsDef => {
diff --git a/packages/types/src/primitive/Generic/Event.ts b/packages/types/src/primitive/Generic/Event.ts
index 6054a12def..62608b9b9b 100644
--- a/packages/types/src/primitive/Generic/Event.ts
+++ b/packages/types/src/primitive/Generic/Event.ts
@@ -81,6 +81,7 @@ export default class Event extends Struct {
     }, value);
   }
 
+  /** @internal */
   public static decodeEvent (registry: Registry, value: Uint8Array = new Uint8Array()): { DataType: Constructor<Null> | Constructor<EventData>; value?: { index: Uint8Array; data: Uint8Array } } {
     if (!value.length) {
       return {
diff --git a/packages/types/src/primitive/Generic/Vote.ts b/packages/types/src/primitive/Generic/Vote.ts
index 46ceda1c96..be7b910f81 100644
--- a/packages/types/src/primitive/Generic/Vote.ts
+++ b/packages/types/src/primitive/Generic/Vote.ts
@@ -45,6 +45,7 @@ export default class Vote extends U8aFixed {
     this._conviction = createType(this.registry, 'Conviction', decoded[0] & CON_MASK);
   }
 
+  /** @internal */
   private static decodeVote (registry: Registry, value?: InputTypes): Uint8Array {
     if (isUndefined(value)) {
       return Vote.decodeVoteBool(false);
@@ -62,12 +63,14 @@ export default class Vote extends U8aFixed {
     return new Uint8Array([vote | conviction.index]);
   }
 
+  /** @internal */
   private static decodeVoteBool (value: boolean): Uint8Array {
     return value
       ? new Uint8Array([AYE_BITS | DEF_CONV])
       : new Uint8Array([NAY_BITS]);
   }
 
+  /** @internal */
   private static decodeVoteU8a (value: Uint8Array): Uint8Array {
     return value.length
       ? value.subarray(0, 1)
diff --git a/packages/types/src/primitive/StorageKey.ts b/packages/types/src/primitive/StorageKey.ts
index d13ffbbcc8..8ed886055e 100644
--- a/packages/types/src/primitive/StorageKey.ts
+++ b/packages/types/src/primitive/StorageKey.ts
@@ -74,6 +74,7 @@ export default class StorageKey extends Bytes {
     this._section = override.section || section;
   }
 
+  /** @internal */
   public static decodeStorageKey (value?: AnyU8a | StorageKey | StorageEntry | [StorageEntry, any]): Decoded {
     if (value instanceof StorageKey) {
       return {
diff --git a/packages/types/src/primitive/Text.ts b/packages/types/src/primitive/Text.ts
index 49f15d5c9d..d82696dcf4 100644
--- a/packages/types/src/primitive/Text.ts
+++ b/packages/types/src/primitive/Text.ts
@@ -31,6 +31,7 @@ export default class Text extends String implements Codec {
     this.registry = registry;
   }
 
+  /** @internal */
   private static decodeText (value: Text | string | AnyU8a | { toString: () => string }): string {
     if (isHex(value)) {
       return u8aToString(hexToU8a(value.toString()));
diff --git a/packages/types/src/types.ts b/packages/types/src/types.ts
index 7aeb96b51a..4e3046cb47 100644
--- a/packages/types/src/types.ts
+++ b/packages/types/src/types.ts
@@ -372,6 +372,12 @@ export interface RegistryMetadataEvents {
   unwrap (): RegistryMetadataEvent[];
 }
 
+export interface RegistryMetadataExtrinsic {
+  version: BN;
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  signedExtensions: String[];
+}
+
 export interface RegistryMetadataModule {
   calls: RegistryMetadataCalls;
   errors: RegistryMetadataErrors;
@@ -381,6 +387,7 @@ export interface RegistryMetadataModule {
 
 export interface RegistryMetadataLatest {
   modules: RegistryMetadataModule[];
+  extrinsic: RegistryMetadataExtrinsic;
 }
 
 export interface RegistryMetadata {
@@ -396,6 +403,8 @@ export interface Registry {
 
   get <T extends Codec = Codec> (name: string): Constructor<T> | undefined;
   getOrThrow <T extends Codec = Codec> (name: string, msg?: string): Constructor<T>;
+  getSignedExtensionExtra (): Record<string, InterfaceTypes>;
+  getSignedExtensionTypes (): Record<string, InterfaceTypes>;
   hasClass (name: string): boolean;
   hasDef (name: string): boolean;
   hasType (name: string): boolean;