Underpaid tax - businesses and self-employed persons

If you underpay tax as a self-employed person, it means the assessed tax was higher than the advance tax you have paid at the time the tax is calculated. The amount you have underpaid, must be paid.

Payment deadlines

If your underpaid tax is more than NOK 1,000, the total is split into two invoices. The deadline for payment depends on when you received your tax assessment notice:

  • If you received your tax assessment notice before 22 June, the deadline for the first instalment will be 20 August and the second instalment is 24 September.
  • If you received your tax assessment notice on 12 August or later, the deadline for the first instalment will be 3 weeks from the date on which your tax assessment was ready, and the second instalment falls due 8 weeks after your tax assessment was ready.

If the payment date is set to a Saturday or Sunday, you may pay it within the Monday (first working day) after the due date. You must pay the underpaid tax even if you’ve made changes to your tax return or submitted an appeal after the due date. If you do not pay the underpaid tax on time, interest will accrue on the overdue amount until you pay.

IIf you do not pay the first instalment by the due date, we consider you to not have paid at all. If you need help, you can contact us.

If you have underpaid tax of less than NOK, 1,000, the deadline for payment depends on when you received your tax assessment notice:

  • If you received your tax assessment notice on 22 June, the payment deadline will be 20 August.
  • If you received your tax assessment notice on 12 August or later, the payment deadline will be 3 weeks after the date your tax assessment notice was ready.

You must pay the underpaid tax even if you’ve made changes to your tax return or submitted an appeal after the due date. If you do not pay the underpaid tax on time, interest will accrue on the overdue amount until you pay.

You do not have to pay if the underpaid tax, including additional interest, amounts to less than NOK 100.

The underpaid tax must be paid within three weeks from the tax assessment notice was sent to the company.

If the payment date is set to a Saturday or Sunday, you may pay it within the Monday (first working day) after the due date.

You must pay the underpaid tax even if you’ve made changes to your tax return or submitted an appeal after the due date. If you do not pay the underpaid tax on time, interest will accrue on the overdue amount until you pay.

You do not have to pay if the underpaid tax, including additional interest, amounts to less than NOK 100.

How to pay

Well before the due date, you’ll receive an invoice with payment information in Altinn. If not, you’ll receive an invoice with payment information by post.

Account number and KID number

Use the account number and KID number stated on the invoice.

If you have not received an invoice with payment information, you can see account numbers and generate KID numbers.

Interest

Right now, the annual interest rate for both underpaid tax and tax credited is 0 percent, determined from 1 July in the income year through to the due date for the first instalment of underpaid tax in the following tax year.

If you've paid too much advance tax and additional advance tax by 31 May in the tax year, there’ll be interest calculated on it upon repayment.

Example: How much interest do I have to pay?

This is an example of how much the interest on underpaid tax might be:

Calculated tax – 2019 income year: NOK 100,000
Advance tax deductions: NOK 80,000
Underpayment: NOK 20,000

Additional interest 1.17 percent from 1 July 2019 to 20 August 2020 (417 days) = NOK 267
To pay: NOK 20,267

Additional interest is added to the underpaid tax. The interest is calculated from 15 March in the year following the income year, until the due date of the underpaid tax.

Example: How must interest do we have to pay?

This is an example of how much the interest on underpaid tax might be:

Calculated tax – 2019 income year: NOK 100,000
Advance tax paid: NOK 80,000
Underpayment: NOK 20,000

Additional interest 1.17 percent from 15 March 2020 to 12 November 2020 (243 days) = NOK 155
To pay: NOK 20,155

Additional advance tax

If you understand that there might be underpaid tax, you can pay additional advance tax by 31 May. Then, you won’t have to pay any additional interest on the underpaid tax.

Payment after the deadline on 31 May will not be taken into account in the final tax settlement.

Remember to select additional advance tax as the type of payment.

If you’ve paid too much advance tax, interest will be added to the amount repaid.

Overdue payment

If the underpaid tax remains unpaid by the due date, penalty interest will accrue and we will implement measures to collect the tax.

Penalty interest will accrue from the due date until the outstanding amount is paid in full. The Ministry of Finance adjusts the rate twice a year.

Examples of measures taken if payment is late:

  • attachment proceedings
  • compulsory sale
  • petition for bankruptcy
  • offsetting

If we have to implement such measures, the company/enterprise may have to pay fees and/or get a mark on its credit record.