From 14 April on, when you log in to MyTax you will activate Suomi.fi Messages. Tax correspondence will be delivered electronically only, in MyTax. Read more about the changes.
My additional prepayment’s due due date is 7 February 2026. Can I send the payment already in January without having to pay interest?
Unfortunately, you cannot. If the due date is a February date, it means that you must pay late-payment interest with relief for the February days. Read more about the late-payment interest with relief.