diff --git a/packages/util/src/format/formatBalance.spec.ts b/packages/util/src/format/formatBalance.spec.ts
index 951b7fec3..708734efc 100644
--- a/packages/util/src/format/formatBalance.spec.ts
+++ b/packages/util/src/format/formatBalance.spec.ts
@@ -189,6 +189,24 @@ describe('formatBalance', (): void => {
         formatBalance(TESTVAL, { decimals: 15, forceUnit: 'µ' })
       ).toEqual('123.4567 µUnit');
     });
+
+    it('formats 123,456 (decimals=0, locale=sl)', (): void => {
+      expect(
+        formatBalance(123456, { decimals: 0, locale: 'sl', withSi: true })
+      ).toEqual('123,4560 kUnit');
+    });
+
+    it('formats BigInt numbers (locale=sl)', (): void => {
+      expect(
+        formatBalance(123456789000n, { decimals: 15, locale: 'sl', withSi: true })
+      ).toEqual('123,4567 µUnit');
+    });
+
+    it('formats 123,456,789,000 (decimals=7, forceUnit=base locale=sl)', (): void => {
+      expect(
+        formatBalance(TESTVAL, { decimals: 7, forceUnit: '-', locale: 'sl' })
+      ).toEqual('12.345,6789 Unit');
+    });
   });
 
   describe('calcSi', (): void => {
diff --git a/packages/util/src/format/formatBalance.ts b/packages/util/src/format/formatBalance.ts
index c90668c58..83d6d1a0b 100644
--- a/packages/util/src/format/formatBalance.ts
+++ b/packages/util/src/format/formatBalance.ts
@@ -7,6 +7,7 @@ import type { SiDef, ToBn } from '../types';
 import { bnToBn } from '../bn/toBn';
 import { isBoolean } from '../is/boolean';
 import { formatDecimal } from './formatDecimal';
+import { getSeparator } from './getSeparator';
 import { calcSi, findSi, SI, SI_MID } from './si';
 
 interface Defaults {
@@ -48,6 +49,10 @@ interface Options {
    * @description Returns all trailing zeros, otherwise removes (default = true)
    */
   withZero?: boolean;
+  /**
+   * @description The locale to use
+   */
+  locale?: string;
 }
 
 interface BalanceFormatter {
@@ -66,7 +71,7 @@ let defaultDecimals = DEFAULT_DECIMALS;
 let defaultUnit = DEFAULT_UNIT;
 
 // Formats a string/number with <prefix>.<postfix><type> notation
-function _formatBalance <ExtToBn extends ToBn> (input?: number | string | BN | bigint | ExtToBn, { decimals = defaultDecimals, forceUnit, withAll = false, withSi = true, withSiFull = false, withUnit = true, withZero = true }: Options = {}): string {
+function _formatBalance <ExtToBn extends ToBn> (input?: number | string | BN | bigint | ExtToBn, { decimals = defaultDecimals, forceUnit, withAll = false, withSi = true, withSiFull = false, withUnit = true, withZero = true, locale = 'en' }: Options = {}): string {
   // we only work with string inputs here - convert anything
   // into the string-only value
   let text = bnToBn(input).toString();
@@ -127,7 +132,9 @@ function _formatBalance <ExtToBn extends ToBn> (input?: number | string | BN | b
       : ` ${withSiFull ? `${si.text}${withUnit ? ' ' : ''}` : si.value}${withUnit ? unit : ''}`
     : '';
 
-  return `${sign}${formatDecimal(pre)}${post && `.${post}`}${units}`;
+  const { decimal, thousand } = getSeparator(locale);
+
+  return `${sign}${formatDecimal(pre, thousand)}${post && `${decimal}${post}`}${units}`;
 }
 
 export const formatBalance = _formatBalance as BalanceFormatter;
diff --git a/packages/util/src/format/formatDecimal.ts b/packages/util/src/format/formatDecimal.ts
index 37776cee4..7e2cbb903 100644
--- a/packages/util/src/format/formatDecimal.ts
+++ b/packages/util/src/format/formatDecimal.ts
@@ -6,9 +6,9 @@ const NUMBER_REGEX = new RegExp('(\\d+?)(?=(\\d{3})+(?!\\d)|$)', 'g');
 
 /**
  * @name formatDecimal
- * @description Formats a number into string format with thousand seperators
+ * @description Formats a number into string format with thousand separators
  */
-export function formatDecimal (value: string): string {
+export function formatDecimal (value: string, separator = ','): string {
   // We can do this by adjusting the regx, however for the sake of clarity
   // we rather strip and re-add the negative sign in the output
   const isNegative = value[0].startsWith('-');
@@ -17,6 +17,6 @@ export function formatDecimal (value: string): string {
     : value.match(NUMBER_REGEX);
 
   return matched
-    ? `${isNegative ? '-' : ''}${matched.join(',')}`
+    ? `${isNegative ? '-' : ''}${matched.join(separator)}`
     : value;
 }
diff --git a/packages/util/src/format/formatNumber.spec.ts b/packages/util/src/format/formatNumber.spec.ts
index d91a93ed7..96f910832 100644
--- a/packages/util/src/format/formatNumber.spec.ts
+++ b/packages/util/src/format/formatNumber.spec.ts
@@ -37,4 +37,22 @@ describe('formatNumber', (): void => {
       })
     ).toEqual('12,345');
   });
+
+  it('formats negative numbers (locale=sl)', (): void => {
+    expect(
+      formatNumber(-123456, { locale: 'sl' })
+    ).toEqual('-123.456');
+  });
+
+  it('formats BN numbers (locale=sl)', (): void => {
+    expect(
+      formatNumber(new BN(12345), { locale: 'sl' })
+    ).toEqual('12.345');
+  });
+
+  it('formats BigInt numbers (locale=sl)', (): void => {
+    expect(
+      formatNumber(123456789n, { locale: 'sl' })
+    ).toEqual('123.456.789');
+  });
 });
diff --git a/packages/util/src/format/formatNumber.ts b/packages/util/src/format/formatNumber.ts
index f30766e07..e241b1bf5 100644
--- a/packages/util/src/format/formatNumber.ts
+++ b/packages/util/src/format/formatNumber.ts
@@ -6,11 +6,24 @@ import type { ToBn } from '../types';
 
 import { bnToBn } from '../bn/toBn';
 import { formatDecimal } from './formatDecimal';
+import { getSeparator } from './getSeparator';
+
+interface Options {
+  /**
+   * @description The locale to use
+   */
+  locale?: string;
+}
 
 /**
  * @name formatNumber
- * @description Formats a number into string format with thousand seperators
+ * @description Formats a number into string format with thousand separators
  */
-export function formatNumber <ExtToBn extends ToBn> (value?: ExtToBn | BN | bigint | number | null): string {
-  return formatDecimal(bnToBn(value).toString());
+export function formatNumber <ExtToBn extends ToBn> (
+  value?: ExtToBn | BN | bigint | number | null,
+  { locale = 'en' }: Options = {}
+): string {
+  const { thousand } = getSeparator(locale);
+
+  return formatDecimal(bnToBn(value).toString(), thousand);
 }
diff --git a/packages/util/src/format/getSeparator.spec.ts b/packages/util/src/format/getSeparator.spec.ts
new file mode 100644
index 000000000..dc761c6f1
--- /dev/null
+++ b/packages/util/src/format/getSeparator.spec.ts
@@ -0,0 +1,72 @@
+// Copyright 2017-2023 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+import { getSeparator } from './getSeparator';
+
+describe('getSeparator', (): void => {
+  it('uses system locale', (): void => {
+    const n = 1000.1;
+    const locale = {
+      decimal: n.toLocaleString().substring(5, 6),
+      thousand: n.toLocaleString().substring(1, 2)
+    };
+
+    expect(
+      getSeparator()
+    ).toEqual(locale);
+  });
+
+  it('uses en locale', (): void => {
+    expect(
+      getSeparator('en')
+    ).toEqual({
+      decimal: '.',
+      thousand: ','
+    });
+  });
+
+  it('uses en-gb locale', (): void => {
+    expect(
+      getSeparator('en-gb')
+    ).toEqual({
+      decimal: '.',
+      thousand: ','
+    });
+  });
+
+  it('uses sl locale', (): void => {
+    expect(
+      getSeparator('sl')
+    ).toEqual({
+      decimal: ',',
+      thousand: '.'
+    });
+  });
+
+  it('uses sl-si locale', (): void => {
+    expect(
+      getSeparator('sl-si')
+    ).toEqual({
+      decimal: ',',
+      thousand: '.'
+    });
+  });
+
+  it('uses it-it locale', (): void => {
+    expect(
+      getSeparator('it-it')
+    ).toEqual({
+      decimal: ',',
+      thousand: '.'
+    });
+  });
+
+  it('uses ja-jp locale', (): void => {
+    expect(
+      getSeparator('ja-jp')
+    ).toEqual({
+      decimal: '.',
+      thousand: ','
+    });
+  });
+});
diff --git a/packages/util/src/format/getSeparator.ts b/packages/util/src/format/getSeparator.ts
new file mode 100644
index 000000000..18a3580d1
--- /dev/null
+++ b/packages/util/src/format/getSeparator.ts
@@ -0,0 +1,15 @@
+// Copyright 2017-2023 @polkadot/util authors & contributors
+// SPDX-License-Identifier: Apache-2.0
+
+/**
+ * Get the decimal and thousand separator of a locale
+ * @param locale
+ * @returns {decimal: string, thousand: string}
+ */
+export function getSeparator (locale?: string):
+{ thousand: string, decimal: string } {
+  return {
+    decimal: (0.1).toLocaleString(locale).substring(1, 2),
+    thousand: (1000).toLocaleString(locale).substring(1, 2)
+  };
+}
diff --git a/packages/util/src/string/camelCase.ts b/packages/util/src/string/camelCase.ts
index 7d8f4822a..36ed7b088 100644
--- a/packages/util/src/string/camelCase.ts
+++ b/packages/util/src/string/camelCase.ts
@@ -33,7 +33,7 @@ function formatAllCaps (w: string): string {
 function converter (format: (w: string, i: number) => string): (value: AnyString) => string {
   return (value: AnyString): string => {
     const parts = value
-      // replace all seperators (including consequtive) with spaces
+      // replace all separators (including consequtive) with spaces
       .replace(/[-_., ]+/g, ' ')
       // we don't want leading or trailing spaces
       .trim()