IBAN (Generic, All Countries) Regex for PHP

What this pattern does

This page provides a well-structured, multi-part regular expression for matching iban (generic, all countries), ported and verified for PHP. 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 PHP project — whether you're validating in a Laravel validator, a WordPress plugin, or a standalone PHP script.

Php Implementation

<?php
// IBAN (Generic, All Countries)
// ReDoS-safe | RegexVault — Finance > Bank Identifiers

define('IBAN_GENERIC_ALL_COUNTRIES_PATTERN', '/^[A-Z]{2}[0-9]{2}[A-Z0-9]{4,30}$/');

function validate_iban_generic_all_countries(string $input): bool {
    return (bool) preg_match(IBAN_GENERIC_ALL_COUNTRIES_PATTERN, $input);
}

// Example
var_dump(validate_iban_generic_all_countries("GB29NWBK60161331926819")); // bool(true)

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Bank Identifiers 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

Structure: 2-char country code + 2 check digits + BBAN (Basic Bank Account Number, country-specific). The check digits are validated via MOD-97 algorithm — regex only validates format. Remove spaces before matching.