Trafi took over the administration of the Watercraft Register from local register offices on 1 August 2014. All registration numbers issued by local register offices remain valid as before.
All watercraft are given a registration number at the time of first registration, which is also recorded in the registration certificate. The registration number must be displayed on both sides of the watercraft so that it is clearly visible when the watercraft is in motion.
Standard registration numbers consist of the letter P followed by at least five numbers. The registration numbers of boats on Tenojoki (Tana) River begin with the letter L. Trial numbers given to entrepreneurs begin with the letter E.