Glossary
IBAN: what an International Bank Account Number is and how it is built
An IBAN (International Bank Account Number) is a standard format for identifying a single bank account across borders, defined by ISO 13616. It starts with a 2-letter country code and 2 check digits, followed by a country-specific basic bank account number, up to 34 characters in total. In SEPA, the IBAN alone is enough to send or collect euro payments.
- IBAN
- International Bank Account Number: an ISO 13616 identifier of up to 34 characters made of a country code, two check digits and the domestic account number, used to route payments to one specific account.
How is an IBAN structured?
Every IBAN has the same first four characters and a national part whose length is fixed per country.
| Country | Length | Structure |
|---|---|---|
| Germany | 22 | DE + 2 check digits + 8-digit bank code + 10-digit account |
| Netherlands | 18 | NL + 2 check digits + 4-letter bank code + 10-digit account |
| France | 27 | FR + 2 check digits + bank, branch, account and national key |
| Belgium | 16 | BE + 2 check digits + 12 digits |
What do the IBAN check digits do?
The two digits after the country code are calculated with the MOD 97-10 method of ISO 7064 over the whole number. A system can therefore reject most typing errors before a payment is sent, which is why checkout and direct debit forms validate the IBAN instantly. A valid checksum does not prove the account exists or belongs to the named person; in the euro area, the Verification of Payee check under the Instant Payments Regulation covers that for credit transfers.
Where is the IBAN used in online payments?
Merchants meet IBANs in SEPA Direct Debit mandates, refunds and payouts to bank accounts, Pay by Bank flows and supplier payments. For SEPA, the IBAN replaced domestic account numbers and the BIC is no longer required from the payer
General information, not legal or financial advice.
Frequently asked questions
Is an IBAN the same as an account number?
No. The IBAN contains the domestic account number but adds the country code, check digits and usually the bank code, so the account can be identified internationally.
Do all countries use IBAN?
No. IBAN is used across Europe and in many countries in the Middle East and elsewhere, but the United States, Canada and Australia, for example, use their own routing and account numbers.
Is it safe to share my IBAN?
An IBAN is meant to be shared to receive money. It can be misused to set up fraudulent direct debits, but SEPA Core debits give the payer an unconditional refund right for 8 weeks from the debit date (PSD2 Art. 76; SEPA Core Rulebook).
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Sources
- Directive (EU) 2015/2366 (PSD2), Article 76: refunds for payee-initiated payment transactions (25.11.2015)
- European Payments Council: SEPA Direct Debit Core Rulebook, refund right of up to eight weeks (accessed 02.11.2026)
- Swift: IBAN Registry, ISO 13616 (accessed 02.11.2026)
- Regulation (EU) No 260/2012 (SEPA Regulation) (14.03.2012)
- Regulation (EU) 2024/886 on instant credit transfers in euro, Verification of Payee (13.03.2024)