IBANPart by part
| Position | Part | Made of | In the example |
|---|---|---|---|
| 1 to 2 | Country code | 2 capital letters: GB | GB |
| 3 to 4 | IBAN check digits | 2 digits | 28 |
| 5 to 8 | Bank code | 4 capital letters | XXXX |
| 9 to 14 | Branch code | 6 digits | 123456 |
| 15 to 22 | Account number | 8 digits | 78901234 |
The parts with a name here are: Bank code, branch code, account number. The bank decides the bank code and the account number; you never have to work them out yourself. The layout code GB2!n4!a6!n8!n is how the registry writes this: a number, then n for digits, a for capital letters or c for letters or digits.
How to check an IBAN of the United Kingdom
- Count the characters without spaces. There must be exactly 22.
- The first two must be GB, and the next two must be digits.
- After those four, the rest must follow the layout: 4 capital letters, then 6 digits, then 8 digits.
- Run the check-digit test. The IBAN checker does all four steps for you and shows which one fails.
Writing it down
On paper, an IBAN is written in groups of four characters with spaces, as in the example above, so that it is easier to read and compare. In online banking and in files it is entered without spaces. Both forms are the same IBAN. Letters are always capitals.
Also used in
The same GB layout, with the same GB country code, is used for accounts in: Isle of Man, Jersey, Guernsey.
How it compares
At 22 characters, it sits between the shortest IBAN in the registry (Norway, 15 characters) and the longest (Russia, 33 characters). The same length is used by Bahrain, Bulgaria, Costa Rica, Georgia, Germany, Ireland, Montenegro, Serbia, each with its own layout. It mixes letters and digits after the check digits.
Common questions
How many characters does an IBAN of the United Kingdom have?
An IBAN of the United Kingdom always has 22 characters: the letters GB, two check digits and 18 more characters for the bank and the account.
What does an IBAN of the United Kingdom start with?
It starts with GB, the country code, followed by two check digits.
Is United Kingdom in SEPA?
Yes. The United Kingdom is part of the Single Euro Payments Area, so euro transfers to and from it use the IBAN.
Layout checked in November 2026 against the SWIFT IBAN Registry data. The example is made up. For a payment, use only the IBAN given by the account holder or the bank, and check with the bank if in doubt.