Mexican Código Postal Regex for JavaScript

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching mexican código postal, ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. 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

// Mexican Código Postal
// ReDoS-safe | RegexVault — Localization > Postal Codes

const mexicanCdigoPostalRegex = /^(0[1-9]|[1-9][0-9])[0-9]{3}$/;

function validateMexicanCdigoPostal(input: string): boolean {
  return mexicanCdigoPostalRegex.test(input);
}

// Example
console.log(validateMexicanCdigoPostal("06600")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Postal Codes 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

Mexican postal codes: 01000-16999 (Mexico City/CDMX), 36000-38999 (Guanajuato), 64000-67999 (Nuevo León), 97000-97999 (Yucatán). 00000 is reserved/invalid. SEPOMEX manages the Mexican postal database.