South African Postal Code Regex for PHP

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching south african postal code, ported and verified for PHP. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// South African Postal Code
// ReDoS-safe | RegexVault — Localization > Postal Codes

define('SOUTH_AFRICAN_POSTAL_CODE_PATTERN', '/^([0-9]{4})$/');

function validate_south_african_postal_code(string $input): bool {
    return (bool) preg_match(SOUTH_AFRICAN_POSTAL_CODE_PATTERN, $input);
}

// Example
var_dump(validate_south_african_postal_code("0001")); // bool(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 PHP developers because especially relevant in PHP where PCRE backtracking limits can trigger silent failures on malicious input. 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

South African postal codes range from 0001 (Pretoria administrative offices) to 9999. Major cities: Johannesburg 2001, Cape Town 8001, Durban 4001, Pretoria 0002. Leading zeros are significant for some areas.