Paste or type any IBAN — validation is instant, completely in your browser. No data sent to any server.
IBAN stands for International Bank Account Number — a standardised format for identifying bank accounts across borders. It consists of a 2-letter country code, 2 check digits, and the BBAN (Basic Bank Account Number) defined by each country.
Validation uses the MOD-97 algorithm: the first 4 characters are moved to the end, letters are converted to numbers (A=10…Z=35), then the entire string is divided by 97 — if the remainder equals 1, the IBAN is valid.
Yes — validation runs entirely in your browser using JavaScript. Your IBAN is never sent to any server and is never stored anywhere. You can safely validate real account numbers.
It confirms that the IBAN is correctly formatted and that the check digits pass the MOD-97 algorithm. It does not confirm that the account actually exists at a bank — only your bank can verify that.
No — spaces are stripped automatically before validation. You can paste an IBAN with or without spaces, in any grouping (e.g. groups of 4 as banks usually show them, or no spaces at all).
A transcription error (wrong digit, extra character) is the most common cause. Copy the IBAN directly from your bank's app or letter rather than retyping it. Also note that some countries use non-standard formats for domestic transfers that differ from the international IBAN format.
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