Finland (FI)
Finnish VAT Number Validation
Format, pattern, and MOD 11-2 checksum algorithm for FI VAT numbers
Finnish VAT numbers (Arvonlisäveronumero or ALV-numero) consist of 8 digits and use a MOD 11-2 weighted checksum algorithm.
Format vs. Active Validation
This checks format only, not if a VAT number is really registered. Use VatDB's API to verify is a number is really registered and active. VatDB checks official EU and national datasources.
Format Overview
| Property | Value |
|---|---|
| Country Code | FI |
| Format | 8 digits |
| Length | 8 digits |
| Example | FI12345678 |
Regex Pattern
^FI[0-9]{8}$
Checksum Algorithm (MOD 11-2)
def validate_fi_vat(number):
if number.startswith('FI'):
number = number[2:]
if len(number) != 8 or not number.isdigit():
return False
weights = [7, 9, 10, 5, 8, 4, 2]
total = sum(int(d) * w for d, w in zip(number[:7], weights))
check = 11 - (total % 11)
if check == 11:
check = 0
elif check == 10:
return False # Invalid number
return check == int(number[7])
Note: If the check calculation results in 10, the VAT number is invalid.
Frequently Asked Questions
How do I verify a Finnish VAT number (ALV-numero)?
Finnish VAT numbers use MOD 11-2 with weights [7,9,10,5,8,4,2]. If the check equals 10, the number is invalid. If 11, check digit is 0. Use VatDB's API for official verification against EU and national databases.
What does a Finnish VAT number look like?
A Finnish VAT number has the format FI12345678 - 'FI' followed by exactly 8 digits. The last digit is a check digit calculated using MOD 11-2.
How many digits are in a Finnish VAT number?
A Finnish VAT number contains exactly 8 digits after the FI country code. The complete number is 10 characters: FI + 8 digits.
What is a Finnish ALV-numero?
ALV-numero (Arvonlisäveronumero) is the Finnish VAT number. ALV stands for 'Arvonlisävero' which means Value Added Tax in Finnish.
Where can I check a Finnish company's VAT number?
Verify VAT numbers using VatDB's API, which checks official EU and national databases in real-time. Returns company details with each validation.
What's the difference between format validation and checking if a VAT number is active?
Checksum validation catches typos but can't detect fake numbers. A mathematically valid number might never have been issued. VatDB's API confirms genuine, current registration.