UK Passport Number Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching uk passport number, ported and verified for JavaScript. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. 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 Passport Number
// ReDoS-safe | RegexVault — Identity & PII > Passport Numbers

const ukPassportNumberRegex = /^[0-9]{9}$/;

function validateUkPassportNumber(input: string): boolean {
  return ukPassportNumberRegex.test(input);
}

// Example
console.log(validateUkPassportNumber("123456789")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Passport Numbers 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

UK passport numbers are 9 digits. The format changed to a simple 9-digit number from an older alphanumeric format. HMPO (His Majesty's Passport Office) issues the numbers sequentially.