IBAN checker: is this IBAN valid, and which bank is it?

How the checker decides

An IBAN is defined by ISO 13616, and Swift keeps the registry of each country's format. The checker takes out spaces, then tests four things in order:

• Country code. The first two letters must be a country or territory in the IBAN Registry.
• Length. Each country has a fixed length, from 15 characters in Norway to 33 in Russia.
• Format. The part after the check digits, the BBAN, has a fixed pattern of letters and digits for each country.
• Check digits. Characters three and four are set so that the whole IBAN, with its first four characters moved to the end and letters turned into numbers (A is 10, Z is 35), leaves a remainder of 1 when divided by 97. Any single wrong digit, or two neighbouring digits swapped, breaks that.

Some countries add their own check digits inside the BBAN, such as France's RIB key. The checker doesn't test those, so a few typos can still slip through in those countries.

What's inside an IBAN

Every IBAN starts with the country code and two check digits. The rest is the account number in the country's own format, usually with a bank code first and sometimes a branch code. For the currencies Align works in:

• UK, 22 characters. GB, the check digits, a 4-letter bank code, the 6-digit sort code and the 8-digit account number. Pounds within the UK usually move by Faster Payments; see GBP account details for companies outside the UK.
• UAE, 23 characters. AE, the check digits, a 3-digit bank code and a 16-digit account number.
• Euro countries, 18 to 27 characters. Each country keeps its own format: 18 in the Netherlands, 20 in Lithuania, 22 in Germany and 27 in France and Italy. In the EU, a bank can't make you give the payee's BIC for a euro transfer, so the IBAN and the name are what matter; see EUR IBANs for companies outside the EU.
• US dollars. The US has no IBANs. USD accounts use a routing number and an account number; see ACH vs Fedwire vs FedNow.

The country code says where the account is held, not who holds it. An IBAN from a payment provider can carry another country's code, and a pooled IBAN may not be in the payee's name at all. Named vs pooled virtual IBANs explains the difference.

Before you pay a new IBAN

• Check the name, not just the number. Euro-area banks run Verification of Payee on euro transfers, and UK banks run Confirmation of Payee, before you send. A close match or no match is a reason to stop and ask.
• Confirm changed details by phone. An email saying a supplier's bank details have changed is the classic invoice fraud. Call a number you already had, not one in the email.
• Send a small test first to a new payee, and wait for them to confirm it arrived.

If a payment has already been sent back, see why international business payments get rejected or returned.

A format check, not a guarantee: a valid IBAN can still belong to someone other than the person you mean to pay. Always confirm the account holder's name.