Thai National ID (บัตรประชาชน) Regex for PHP

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching thai national id (บัตรประชาชน), ported and verified for PHP. 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 PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// Thai National ID (บัตรประชาชน)
// ReDoS-safe | RegexVault — Identity & PII > National Identity Numbers

define('THAI_NATIONAL_ID_PATTERN', '/^[1-9][0-9]{12}$/');

function validate_thai_national_id(string $input): bool {
    return (bool) preg_match(THAI_NATIONAL_ID_PATTERN, $input);
}

// Example
var_dump(validate_thai_national_id("1234567890123")); // bool(true)

Test Cases

When to use this pattern

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

Thai ID structure: region (1-8 for citizenship type), province/district/registration sequence (11 digits), check digit. First digit 1-8 = born in Thailand, 0 = illegal immigrant, 9 = not eligible. Checksum: sum of first 12 digits × weights (13-2), last digit = (11 - (sum mod 11)) mod 10.