ISO 4217 Currency Code Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching iso 4217 currency 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

// ISO 4217 Currency Code
// ReDoS-safe | RegexVault — Finance > Currency & Money

const iso4217CurrencyCodeRegex = /^[A-Z]{3}$/;

function validateIso4217CurrencyCode(input: string): boolean {
  return iso4217CurrencyCodeRegex.test(input);
}

// Example
console.log(validateIso4217CurrencyCode("USD")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Currency & Money 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

ISO 4217 codes are always 3 uppercase letters. Cryptocurrency codes (BTC, ETH) are not part of the ISO standard but some systems treat them as currency codes. X-prefixed codes are special (XAU=gold, XDR=SDR).