IBAN (Generic, All Countries) Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching iban (generic, all countries), 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

// IBAN (Generic, All Countries)
// ReDoS-safe | RegexVault — Finance > Bank Identifiers

const ibanGenericAllCountriesRegex = /^[A-Z]{2}[0-9]{2}[A-Z0-9]{4,30}$/;

function validateIbanGenericAllCountries(input: string): boolean {
  return ibanGenericAllCountriesRegex.test(input);
}

// Example
console.log(validateIbanGenericAllCountries("GB29NWBK60161331926819")); // 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

Structure: 2-char country code + 2 check digits + BBAN (Basic Bank Account Number, country-specific). The check digits are validated via MOD-97 algorithm — regex only validates format. Remove spaces before matching.