Web開発
IBAN Validator
ISO 7064(mod 97)チェックサム、フォーマット、および国ごとの想定される桁数でIBANを検証します。すべてブラウザ内で計算されます。
よくある質問
What does the mod-97 checksum actually verify?
It's the ISO 7064 algorithm: the IBAN is rearranged and converted into a number, and that number must leave a remainder of 1 when divided by 97 — this catches typos and swapped characters but doesn't confirm the account exists.
Why does the expected length differ by country?
Each country's national banking format defines a fixed IBAN length, for example Germany uses 22 characters and the United Kingdom also uses 22, so the tool checks the total length against the country code found at the start of the IBAN.
What if my country isn't in the length list?
The checksum check still runs normally; only the length check is skipped for countries missing from the tool's reference table, and that doesn't affect the checksum result.