Foreign businesses with activities in Norway are required to report their assignments and employees to Norwegian tax authorities. The report is filed to the Central Office – Foreign Tax Affairs (COFTA) through an online portal, or by completing and submitting a paper form named RF-1199 for reporting of contract and RF-1198 for reporting of employees.
Anyone who receives income from work in Norway or on the Norwegian continental shelf is required to file a Norwegian tax return.
The Norwegian tax year coincides with the calendar year, and the tax return must be submitted by 30 April in the year after the income was received. This means that if you work in Norway this year, then you will likely need to file a tax return by 30 April next year.