Additional advance tax for self-employed persons and businesses
If you realise that you have underpaid tax, you may wish to consider paying additional advance tax. In this case, you do not have to pay interest on the underpaid tax.
The deadline for payment is 31 May.
You're considered to have underpaid tax when the calculated tax exceeds the advance tax you’ve paid, and, if applicable, any withheld tax (this will only apply if you’re an employee as well).You’ll have underpaid tax when your calculated tax exceeds the withholding tax and advance tax.
You’ll have to pay underpaid tax within three weeks after the tax assessment notice is sent out.
How to pay additional advance tax
Use the KID number and account number that you received with your tax return.
If you do not have the payment information, you can generate a KID number and find the account number.
Avoid interest
If you're self-employed, you can avoid paying interest on underpaid tax by paying additional advance tax by 31 May. If 31 May is a Saturday, Sunday or holiday, the deadline is the next working day.
Sometimes, the additional advance tax payment you make will not be accepted. This could be because you’ve paid after the deadline of 31 May, or because you used an incorrect KID number. In this case, you can get the amount refunded before the tax assessment. The amount may also be used as an advance payment of underpaid tax.
You can appeal if your advance tax payment is not accepted. The appeal deadline is three weeks from the date on which you were notified that the payment was not accepted. If you were notified when you received the tax assessment notice, the deadline runs from this date.
You must include the following in your appeal:
- Why you believe that the amount should be approved as an additional advance tax payment.
- Norwegian national identity number/organisation number and tax year.