Finnish IBAN Format (FI): Structure, Bank Codes, and Validation Examples

The Finnish IBAN is 18 characters long and encodes Finland's domestic tilinumero (account number) system, where a 3-digit bank code combines with an 11-digit domestic account identifier. Finland is a founding eurozone and SEPA member, and Finnish IBANs are used in high-volume manufacturing and tech sector payments across Northern Europe. The Finnish format is compact and fully numeric, making it one of the simpler European IBANs to validate programmatically.

Finnish IBAN at a Glance

• Country code: FI
• Total length: 18 characters (always)
• Format: FIkk bbb cccccccccc x
• BBAN length: 14 digits
• Character types: digits only after the country code

Finnish IBAN Structure Explained

1. Country Code, FI (2 characters)

The ISO 3166-1 alpha-2 code for Finland. Every Finnish IBAN begins with FI.

2. Check Digits, kk (2 digits)

Two decimal digits calculated using the MOD-97 algorithm. Standard across all IBANs.

3. Bank Code, bbb (3 digits)

A 3-digit bank code identifying the Finnish bank. Assigned by the Finnish Financial Supervisory Authority (Finanssivalvonta). The first 1–3 digits of the Finnish domestic account number indicate the bank. Examples:

• 123, Nordea (account numbers starting 1 or 2 are Nordea)
• 405, Aktia Bank (497 is also an Aktia code)
• 500, OP Financial Group (Osuuspankki)
• 800, Danske Bank (the former Sampo account range)

4. Account Number, cccccccccc (10 digits)

The 10-digit account number (tilinumero) of the individual account. Finnish account numbers are zero-padded on the left when the original number has fewer than 10 digits.

5. Check Digit, x (1 digit)

A single domestic check digit at the end of the BBAN, calculated using a modulo-10 Luhn variant algorithm. This check digit is inherited from the Finnish domestic account number system and provides an additional integrity check beyond the IBAN-level MOD-97.

Finnish IBAN Example Explained

FI21 1234 5600 0007 85

• Country: FI
• Check digits: 21
• Bank code: 123 (Nordea)
• Account number: 4560000078
• Domestic check digit: 5

Second Example, OP Financial Group

FI34 5000 0120 3456 72

• Country: FI
• Check digits: 34
• Bank code: 500 (OP Osuuspankki)
• Account number: 0012034567
• Domestic check digit: 2

How Finnish IBAN Validation Works

1. Country code check: First two characters must be exactly FI.
2. Length check: Total character count (spaces removed) must be exactly 18. Finnish IBANs are the same length as Dutch and Danish IBANs (both 18 characters), but all three have different bank code structures.
3. Character type check: Positions 3–18 must all be decimal digits. Finnish IBANs are fully numeric after the country code.
4. MOD-97 check: Standard modulo 97 computation. Result must equal 1.

The ibanchecker.cash validator validates Finnish IBANs and identifies the bank from the 3-digit bank code.

Common Finnish IBAN Mistakes

Entering the Domestic Tilinumero Instead of IBAN

The Finnish domestic tilinumero is written in the format 123456-78905 (with a hyphen). This domestic format is not usable for SEPA or international payments. Always use the full 18-character IBAN starting with FI.

Confusing 18-Character Finnish, Dutch, and Danish IBANs

Finland (FI), Netherlands (NL), and Denmark (DK) all have 18-character IBANs. The key difference is the bank code format: Dutch IBANs have 4-letter bank codes (ABNA, INGB); Finnish and Danish IBANs are fully numeric. Always check the country code first.

Spaces in Electronic Transmission

Remove all spaces: FI2112345600000785.

Finnish IBAN and SEPA

Finland is a founding eurozone and SEPA member. All Finnish bank accounts support SEPA Credit Transfers and Direct Debits in euros. For payments outside SEPA, look up any Finnish bank's BIC using the ibanchecker.cash SWIFT directory.

Validating Finnish IBANs in Bulk

Finance teams with Northern European supplier lists can validate Finnish IBANs alongside Swedish, Danish, and Norwegian ones using the ibanchecker.cash bulk checker. Upload a CSV with up to 100 IBANs and get instant validation per row.

Sources & References

• SWIFT IBAN Registry — Official IBAN country format specifications
• ISO 13616 — IBAN international standard
• EPC SEPA Participants — Finland in SEPA scheme registers
• Bank of Finland (Suomen Pankki) — Finland's central bank and payment system regulator
• ECB TARGET2 — Eurozone payment infrastructure used by Finnish banks

Last updated: June 2026