ytunnus

Y-tunnus, commonly written Ytunnus, is the Finnish business identification number used to uniquely identify legally registered entities in Finland. It is assigned to companies, associations, foundations, and sole traders when they register with the authorities and is used in official communications, taxation, and public records.

The Y-tunnus is issued by the Finnish Patent and Registration Office (PRH) in cooperation with the Finnish Tax Administration (Verohallinto). It is granted at the time an entity is registered in the trade and business registers.

Typical format is seven digits, a hyphen, and a final check digit, for example 1234567-8. The Y-tunnus is a public identifier that remains with the legal entity throughout its existence, even if ownership or business activity changes; it is not a personal identity number.

Uses include taxation, value-added tax (VAT) registration, payroll and social security contributions, invoicing, and other dealings with authorities and business partners. The Y-tunnus is widely used across the public sector to identify entities in records, reports, and digital services.

Information about a registered entity and its Y-tunnus can be found in official Finnish business information services, such as PRH’s and Verohallinto’s registers. The number may be required when filing corporate taxes, submitting annual reports, or issuing invoices.