EU citizens and citizens of Liechtenstein and Switzerland do not need a residence permit, but they must register their right to reside in Finland if their stay is going to last longer than three months.
If you are from another Nordic country (Sweden, Norway, Denmark or Iceland), you must notify the local register office no later than one week after moving to Rovaniemi.
Non-EU citizens have to apply for a residence permit in advance. If your studies in Finland take longer than 90 days, you need a residence permit for studies. This residence permit is valid for two years, unless you apply for it for a shorter period. However, the residence permit is only valid for the duration of your studies, if your studies take less than two years. If you do not have a residence permit, you can study in Finland for a maximum of 90 days. Even if you stay in Finland for less than 90 days, you may still need a visa. The Finnish Immigration Service will grant you a residence permit for studies, if you have been accepted to study at a higher education institution.