The Finnish VAT number

The format

A Finnish VAT number is always ten characters: the country code and eight digits.

• FIThe country code.
• 0480551Seven digits of the Business ID.
• 9The check digit.

The check digit is computed modulus 11 with weights 7, 9, 10, 5, 8, 4, 2. A remainder of 1 means no such identifier exists. Domestically the Business ID is written with a hyphen before the check digit (0480551-9) and the hyphen is dropped in the VAT number.

Business ID and VAT number

The Business ID (Y-tunnus) is issued to every company and organisation when it enters the business information system. It never changes.

The VAT number is that same identifier with an FI prefix, but it exists only if the business is entered in the VAT register. The distinction matters: everyone has a Business ID, not everyone is VAT liable.

A company may also be in the prepayment register and the employer register, independently of one another. Neither affects the VAT number.

Finding the company

PRH open data

The Patent and Registration Office publishes the trade register as open data with no registration required. Single companies can be fetched from the API, but the endpoint that matters is /all_companies: it returns the entire register as one zipped JSON file, hundreds of thousands of companies in a few tens of seconds. Paginating the same work would take thousands of requests and hours.

One caveat: the trade register is not the VAT register. Not every company in the file is VAT liable, and ceased companies stay in it with a status flag.

YTJ

ytj.fi is the human-facing interface to the same data: name, industry, address and register entries, VAT liability included.

VIES

Finland discloses name and address through VIES. The address sometimes carries a c/o run together with the next word without a space, which is worth allowing for when parsing.

Finland-specific pitfalls

• Drop the hyphen. FI0480551-9 is not valid; a VAT number is digits only.
• A Business ID does not imply VAT liability. The trade register and the VAT register are different registers.
• Ceased companies remain in the open data, so the status has to be checked separately.
• Do not paginate the API. The whole register is available in one request; paginating takes hours.
• Addresses can contain a c/o glued to the following word.

One API, one response shape

Vatlas turns a business tax number into a company record: legal name, national identifier, legal form, status and address. Finland: the same call and the same response as for every other country covered.

curl "https://api.vatlas.dev/v1/lookup/FI04805519" \
  -H "Authorization: Bearer $VATLAS_KEY"

Response:

200 OK

{
  "data": {
    "vatNumber": "FI04805519",
    "countryCode": "FI",
    "nationalNumber": "04805519",
    "nationalId": "0480551-9",
    "name": "Conimex Oy",
    "legalForm": "Limited company",
    "status": "active",
    "address": {
      "line1": "Kruunuvuorenkatu 9",
      "line2": "c/o Conimex Oy",
      "postalCode": "00160",
      "city": "HELSINKI",
      "country": "FI"
    }
  },
  "meta": {
    "source": "PRH",
    "sourceDate": "2026-09-15",
    "sourceSince": "2026-09-06",
    "sourceUpdatedAt": "1981-09-24T00:00:00.000Z"
  }
}

meta.source names the register that answered (SIRENE, ARES, VIES…) and meta.sourceDate the day it said so: the publication date of the file for a register we import, the day of the call for one we query live. The shape of the response never changes from one country to the next.

Get a free key Read the documentation

VAT numbers in other countries

• France
• Germany
• Italy
• Spain
• Netherlands
• Belgium
• All countries

Last updated 28 August 2026.