Check the housing information (housing type, area of primary rooms and age) which the Norwegian Tax Administration holds about your property. You will find this information under "Grunnlag for likningsverdi" (Basis for tax value) in the 2015 tax return, which you received in spring 2016.
Calculate the tax value for 2015
During the first year in which the municipal authority uses values from the Norwegian Tax Administration as a basis for calculating property tax, the deadline for appeals is six weeks after you receive the property tax notification.
For subsequent years, the ordinary appeal rules laid down in the Tax Administration Act will apply. The deadline for appealing against an assessed capital value (tax value) will normally have expired by the time you receive your property tax notification, so you should ask the Norwegian Tax Administration to amend the assessment from the previous year instead. The Norwegian Tax Administration will then assess whether there are sufficient grounds to reconsider the case.
You must pay the property tax by the due date even if you appeal.
You must explain why you are appealing and state what you believe is wrong.
You must be able to present documentation of the change that has been made if the tax office asks to see it.