Free tool
IBAN validator: check an account and its bank
Paste an IBAN and see at once whether it's written correctly, which country and bank it belongs to and its BIC. Or work out the IBAN of a Spanish account.
What a Spanish IBAN looks like
A Spanish IBAN has 24 characters: the letters ES, two check digits and the 20 digits of the traditional account number, the CCC 1,2. It's usually written in groups of four to make it easier to read, but the spaces aren't part of the IBAN.
ES91 2100 0418 4502 0005 1332.| Part | Example | What it means |
|---|---|---|
| Country | ES | Spain, by its country code. |
| IBAN check | 91 | Two digits that check the whole IBAN. |
| Bank | 2100 | The bank: the number under which it is listed in the Banco de España register. |
| Branch | 0418 | The account's branch. |
| Account check | 45 | Two digits that check the bank, branch and account number. |
| Account number | 0200051332 | The account within that branch. |
How we know an IBAN is valid
Every IBAN carries two check digits. To test them, the first four characters move to the end, each letter becomes a number (A is 10, B is 11 and so on to Z, which is 35), and the resulting number divided by 97 must leave a remainder of 1 1. That catches the most common mistakes, such as a mistyped digit or two digits swapped.
Spanish IBANs also carry the old account number's own check: the first of its two check digits comes from the bank and branch, and the second from the account number, with a modulo 11 formula 1. The validator tests both, and also that the IBAN has its country's length according to SWIFT's official registry 2.
IBAN and BIC: what you need for a transfer
The BIC, also called the SWIFT code, identifies the bank, not the account. It has 8 or 11 characters, and the fifth and sixth are the country: ES for Spain. For a euro transfer within the SEPA area, the IBAN is enough. If you send money outside that area or in another currency, the bank may also ask for the receiving bank's BIC. You'll find every Spanish institution's in the directory of bank codes.
The SEPA area brings together the countries where euro payments follow the same rules: the European Union and others such as Switzerland, Norway and the United Kingdom. The validator tells you whether the IBAN is from one of them, according to SWIFT's registry 2.
If your account number is an old one
The 20 digits of the account number are still your account: the IBAN only adds ES and two check digits in front. If you have an old number, the second form works out its IBAN. And if its bank code belongs to a bank that no longer exists, such as Banesto (0030), Banco Popular (0075) or Bankia (2038), we tell you which bank took it over: the full list is under codes of banks that no longer exist.
Is it safe to type my IBAN here?
Yes. The check runs in your browser and the IBAN isn't sent anywhere. Besides, an IBAN gives no access to your money: it's what you give people to pay you. What you must never share are your passwords, the codes your bank sends you and your card details.
Can I find out whose an IBAN is?
No. Neither the IBAN nor its check says who holds it. When you make a euro transfer, your bank checks for free whether the name you type matches the holder's 3.
Why is the IBAN valid but no bank shown?
Because its bank code isn't on our list, which covers the institutions in the Banco de España register and the codes of those that have disappeared since 2000 4.
How many characters does an IBAN have?
It depends on the country: 24 in Spain, 22 in Germany, 27 in France and Italy and 25 in Portugal, for example 2. It always starts with the country's two letters and two check digits.
Sources
- AEB, CECA y UNACC. Identificación normalizada de cuentas: CCC e IBAN. Serie normas y procedimientos bancarios nº 37, noviembre de 2001. www.administradoresfincasasturias.es/udecontrol_datos/FileManager/File/PDF/37_CCC_%20IBAN.PDF
- SWIFT. IBAN Registry, el registro oficial de los formatos de IBAN (ISO 13616). www.swift.com/standards/data-standards/iban-international-bank-account-number
- Banco de España, Portal del Cliente Bancario. Nuevo servicio gratuito de verificación del beneficiario a partir del 9 de octubre de 2025. 7 de octubre de 2025. clientebancario.bde.es/pcb/es/blog/nuevo-servicio-gratuito-de-verificacion-del-beneficiario-a-partir-del-9-de-octubre-de-2025-.html
- Banco de España. Registro oficial de entidades: ficheros de entidades de crédito y de entidades de pago, 5 de noviembre de 2026. app.bde.es/rbe_spa/
General information, not financial advice. The calculators give estimates: what counts are the terms of your bank's offer. bancos.app is not a bank and isn't linked to any bank.