United Kingdom IBAN Calculator

Enter a UK bank code and account number to generate a correctly formatted GB IBAN — right length, valid check digits, instantly in your browser.

Calculate a UK IBAN

Every UK IBAN starts with GB and two check digits, followed by a 4-character bank code and the account number — 22 characters in total.

Enter the local details below. The calculator pads the account number, computes the ISO 7064 check digits, and prints the result in standard four-character groups.

GB IBAN format

A UK IBAN packs the whole routing path into one string: GB, two check digits, the 4-character bank code, and a 8-character account section.

In the printed format, k marks the check digits, b the bank code, s the branch, c the account number, and x a national check character.

IBAN length
22 characters
Bank code
4 characters
Account number
Up to 8 characters
Check digits
2 digits after GB
Printed format
GBkk bbbb ssss sscc cccc cc
Example IBAN
GB29 NWBK 6016 1331 9268 19

Frequently asked questions

  • A UK IBAN is 22 characters: the country code GB, two check digits, a 4-character bank code, and the account section. Printed in groups of four, it looks like GB29 NWBK 6016 1331 9268 19.

  • With the ISO 7064 mod 97-10 algorithm. The bank code, account number, and country code are converted to digits, and the two check digits are chosen so the full number leaves a remainder of 1 when divided by 97. The calculator does this for you and rejects any input that cannot produce a valid GB IBAN.

  • Yes. It runs entirely in your browser — the bank details you enter are never sent to a server, stored, or shared. There is no sign-up and no fee.

  • Yes — the calculator covers 41 countries. Pick a different country in the form above, or open its dedicated page from the list below.

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