UK Sort Code Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching uk sort code, ported and verified for JavaScript. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// UK Sort Code
// ReDoS-safe | RegexVault — Finance > Bank Identifiers

const ukSortCodeRegex = /^(?:[0-9]{6}|[0-9]{2}-[0-9]{2}-[0-9]{2})$/;

function validateUkSortCode(input: string): boolean {
  return ukSortCodeRegex.test(input);
}

// Example
console.log(validateUkSortCode("60-16-13")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Bank Identifiers category and carries a ReDoS-safe certification. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Sort codes identify the bank and branch. The first two digits identify the bank (20=Barclays, 30=Lloyds, 40=HSBC, 60=NatWest). Normalize to 6 digits (strip hyphens) before storage.