IBAN Validator

The International Bank Account Number (IBAN) is a standardised format for identifying bank accounts internationally. Defined by ISO 13616 and maintained by SWIFT, it consists of up to 34 alphanumeric characters: a two-letter country code, a two-digit check number, and a country-specific Basic Bank Account Number (BBAN) of up to 30 characters. Germany's IBANs are 22 characters; Norway's are 15; Russia's are 33. The point of the standard is to make cross-border payment routing unambiguous — given any valid IBAN, a SWIFT-aware bank anywhere can determine the destination country and account without manual lookup.

The mod-97 check — how validation works

The two-digit check number isn't decorative. To validate an IBAN, you move the first four characters (country + check digits) to the end of the string, replace every letter with its position-based number (A=10, B=11, …, Z=35), and compute the result mod 97. A valid IBAN always produces a remainder of exactly 1. This is the entire mathematical guarantee of IBAN integrity — it catches every single-digit typo, every transposition of two adjacent digits, and around 99% of all multi-character errors. It is not a cryptographic checksum, so a determined fraudster can construct a valid-looking IBAN, but accidental data-entry errors are caught with extremely high probability.

SEPA — the European payment area

SEPA (Single Euro Payments Area) is a payment integration initiative covering 36 countries, all of which use IBAN. For SEPA Credit Transfers and SEPA Direct Debit, you only need the recipient's IBAN — no BIC required since 2016. SEPA Instant Credit Transfer (SCT Inst) settles in under 10 seconds and is available 24/7. Bank-level interoperability across SEPA is the reason a European business can issue invoices payable by any other European customer without per-country bank-account configuration. The same scheme has no equivalent in ASEAN — each ASEAN country runs its own domestic instant payment scheme.

Why ASEAN uses something different

Singapore, Malaysia, Indonesia, Thailand, Vietnam, and the Philippines never adopted IBAN. Each country's central bank built a parallel system for instant retail payments around 2017–2019. Singapore launched PayNow (transfer by mobile number, NRIC, or business UEN — settled instantly via FAST), Malaysia launched DuitNow (mobile number, IC, or business ID), Thailand launched PromptPay (mobile or national ID), the Philippines launched InstaPay/PESONet, Indonesia launched BI-FAST, and Vietnam runs through NAPAS 247. Cross-border, an ASEAN payment goes via SWIFT MT103 or — increasingly — via PayNow-PromptPay-style bilateral linkages (Singapore-Thailand launched 2021, Singapore-India launched 2023). There is no single ASEAN IBAN equivalent because each country deliberately built its own scheme to avoid foreign infrastructure dependency.

Virtual IBANs and modern fintech

One twist worth knowing: virtual IBANs. Modern fintechs like Wise (formerly TransferWise), Revolut, and N26 issue customers IBANs in countries the customer doesn't bank in — a UK Wise user can be issued a EUR-denominated IBAN starting with BE (Belgium) for receiving European payments. These are technically valid IBANs that pass mod-97, route to the fintech's clearing account, and then settle internally to the end-customer's wallet. For users sending the payment, it looks indistinguishable from a regular bank IBAN. The tool above will validate these as mathematically correct — confirming whether the account actually exists requires the recipient bank to respond.