Validate an IBAN (International Bank Account Number) while enforcing that its country prefix matches your selected jurisdiction.
Checks performed
- Country match — the first two letters must equal the ISO country code you chose (for example
DEwhen Germany is selected). - Length — total character count must match the official length table for that country.
- Character set — only alphanumeric characters after normalization; spaces are ignored.
- MOD-97 checksum — digits and letters are rearranged, letters expand to numbers (
A→10 …Z→35), and the big integer must leave remainder 1 when divided by 97.
When to use it
Gate bank-detail forms, pre-validate SEPA payment files, or teach how IBAN embeds country, checksum, and domestic account data in one string.
Limitations
A valid checksum does not guarantee the account is open, reachable, or owned by the payee. Closed accounts and transposed domestic digits can theoretically pass rare edge cases. This tool does not call banking networks or the IBAN registry in real time.