How long is a Finnish IBAN?

A Finnish IBAN is exactly 18 characters: the country code FI, two check digits, and a 14-digit all-numeric BBAN. The first 3 digits of the BBAN form the bank group code. It is one of the shorter SEPA IBANs.

Is the Finnish BBAN always numeric?

Yes. Unlike the Gulf or Maltese IBANs that allow letters in the account field, the entire 14-character Finnish BBAN is digits only. The tool flags any letter in the BBAN as invalid.

How does the MOD-97 checksum work?

The first four characters (FI plus the check digits) move to the end, each letter expands to a two-digit number (A=10 to Z=35, so F=15 and I=18), and the result is divided by 97. The IBAN is valid only when the remainder is 1.

Does a pass mean the account exists?

No. It confirms the format and checksum only. Whether the account is open or who owns it can only be confirmed by the issuing bank.

Is my IBAN sent anywhere?

No. The validator runs entirely in your browser. Your IBAN is never uploaded, stored, or logged, so confidential account details stay on your device.

Finland IBAN Validator

Finnish IBANs are short and strictly numeric: 18 characters with an all-digit 14-character BBAN whose first three digits identify the bank group. Finland uses IBANs heavily in its Finvoice e-invoicing standard and across SEPA, so a single transposed digit causes a rejected payment. This validator confirms the structure, checks that the BBAN is digits only, and runs the ISO 7064 MOD-97-10 checksum before you submit anything.

Paste any IBAN beginning with FI and the tool validates it locally in your browser.

How it works

A Finnish IBAN has three logical parts:

Country code — the fixed letters FI
Check digits — two digits from the MOD-97 algorithm
BBAN — a 14-digit all-numeric block, where the first 3 digits are the bank group and the rest are the account number plus a national check digit

The checksum moves the first four characters to the end, expands each letter to its numeric value (F=15, I=18), and divides the resulting number by 97. A valid IBAN leaves a remainder of exactly 1. Because the number is far larger than a normal integer, the tool folds the modulus one digit at a time so it never overflows.

Tips and notes

A length other than 18 fails immediately — the most common paste error.
Any letter inside the BBAN is invalid for Finland; the tool flags it.
A valid checksum confirms format only, not account existence. Use the iban-bic-lookup-tool to derive the BIC.