You can continue using your KATSO ID and KATSO authorisations to access Tax Administration e-services until the end of 2020. After that, you must use the Suomi.fi authentication and authorisation services instead.
Most companies and businesses registered in the Business Information System or in the trade register can already use Suomi.fi authorisations for their tax matters.
During 2020, Suomi.fi authorisations will also be made available to those who cannot yet use them.