You must pay annual fees each year. The fees are due in advance. The first payment is due two years after the application was filed. This means that the first payment deadline is at the beginning of the third year for which fees are due. You pay the annual fees for the first and second years at the same time as the fee for the third year. The fee year is calculated from the month the application is filed with the Norwegian Industrial Property Office and the payment deadline is set to the last day of this month.
Payment for the fourth and subsequent years is due in advance in the same calendar month each year.
If you file a patent application on 1 June 2008, the first deadline for paying the annual fee will be 30 June 2010. This payment covers the annual fee for three years, the first two years in arrears and an advance payment for the third year. The fee for the fourth year is due 30 June 2011, etc.