IBAN (International Bank Account Number)

An IBAN (International Bank Account Number) is an internationally agreed format for bank account numbers, defined by ISO 13616. It combines a two-letter country code, two check digits and a country-specific basic bank account number (BBAN), up to 34 characters in total.

Why it matters

It lets a payment system verify an account number's structure before sending money, which reduces misrouted transfers. IBANs are mandatory across the SEPA area and used in many other countries, but not in all: the United States and India, for example, do not use them for domestic accounts and rely on their own routing systems. The check digits are computed with a mod-97 algorithm, so most typos are caught immediately. An IBAN does not by itself prove the account exists or who owns it.

Example

A published sample IBAN for the UK:

GB82 WEST 1234 5698 7654 32

• GB: country.
• 82: check digits.
• WEST 1234 5698 7654 32: bank identifier plus account number.

Spaces are only for readability; systems store the string without them.

Common mistakes

• Assuming a valid checksum means the account is real.
• Entering lowercase letters or spaces into strict forms.
• Expecting every country to use an IBAN; many need a SWIFT code and a local account number instead.

Rules vary by country; this entry is a definition only.

Related

• ACH
• SEPA
• IFSC code
• Remittance

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