Check an IBAN before using it
A mistyped IBAN bounces a transfer days later. The mod-97 check catches typos in a second.
Tools used in this guide
The job
Paste the IBAN — spaces from a formatted display are fine. The tool checks the country-specific length, then the mod-97 checksum that catches transposed digits.
Example: GB29 NWBK 6016 1331 9268 19 is a well-known valid-format IBAN. Change any digit and the check fails.
What validation proves
The checksum proves the string is internally consistent — nothing more. It cannot tell you the account exists, is open, or belongs to who you think. For that, only the bank's own confirmation counts.
A caution
IBANs identify real bank accounts. Use published test IBANs for development, and avoid pasting anyone's real account number into web tools — even local ones like this.