Business ID (Y-tunnus)
A unique identifier for companies and organizations in Finland.
Detailed explanation
The Y-tunnus consists of seven digits followed by a hyphen and a check digit (e.g., 1234567-8). This format ensures each identifier is unique and includes built-in error detection. The number is assigned by the Finnish Patent and Registration Office (PRH) or the Tax Administration when a business entity is registered, and it remains with the organization throughout its existence.
Every legally operating business in Finland must have a Y-tunnus. This includes sole proprietors (toiminimi), limited liability companies (osakeyhtiö), partnerships, cooperatives, associations, and even foreign companies with a permanent establishment in Finland. The number appears on virtually all official business documents and is used to track tax obligations, employer responsibilities, and regulatory compliance.
The Y-tunnus is publicly searchable through the Business Information System (YTJ - Yritys- ja yhteisötietojärjestelmä), a free online database maintained jointly by PRH and the Tax Administration. This transparency allows anyone to verify a company's legitimacy, check its registration status, and access basic information about its activities and responsible persons.
How it affects expats
- Freelancing and self-employment: Starting any business activity requires obtaining a Y-tunnus
- Verifying employers: You can check potential employers' legitimacy using their Y-tunnus in the YTJ database
- Invoice requirements: When invoicing businesses, you often need to include your Y-tunnus
- Tax obligations: The Y-tunnus links your business to tax records and VAT registration
- Contracts and banking: Business bank accounts and many contracts require your Y-tunnus
- Starting a company: Essential first step before conducting any commercial activity in Finland
How to get a y-tunnus
- Decide your business form: Sole proprietor is simplest; OY (limited company) offers liability protection
- Register online: Use the YTJ service (ytj.fi) to submit your registration electronically
- Prepare required information: Business name, industry description, estimated turnover, and personal details
- Pay the registration fee: Fees vary by business type (sole proprietors are free; OY costs around 280 EUR online)
- Receive your Y-tunnus: Processing takes 1-5 business days for most business forms
- Register for tax obligations: Separately register for VAT if your annual turnover exceeds 20,000 EUR
Where you will see y-tunnus
- Business invoices and receipts
- Company websites (often in the footer)
- Employment contracts
- Official correspondence from companies
- Public procurement documents
- Trade register extracts
Related terms
- ALV (VAT): Value-added tax in Finland
- YEL (Self-employed pension insurance): Pension insurance for self-employed people
- Foreigner's ID number (HETU): The Finnish personal identity code used by authorities and many services
- Tax card (Verokortti): Shows your withholding rate