Mortgage interest deductions in Norway: checking your tax card and tax return

A mortgage interest deduction reduces ordinary income, one of the bases used to calculate Norwegian tax. It does not repay the entire interest bill. For the 2026 income year, the standard ordinary-income rate is 22 per cent; the rate in the designated action zone in Troms and Finnmark is 18.5 per cent. The actual effect depends on your tax circumstances.

Start with the bank's information, the correct income year and your share of the loan. Compare these with your tax deduction card or tax return, depending on the task. This guide uses Norwegian Tax Administration information checked on 11 November 2026. The 2026 rates are not presented as enacted rates for 2027.

Which year are you checking?

At the beginning of 2027, two tasks can easily become confused. One concerns expected income, debt and interest for the new year. The other concerns what actually happened in 2026 and needs checking in the return for that income year.

Put the year at the top of your own notes. A 2026 annual statement is not a confirmed repayment schedule for 2027. A new loan, an interest-rate change or an extra repayment can make the next year's figures different.

Interest and principal repayments are different

A payment to the bank can contain several elements. Principal repayments reduce the debt itself. Interest is the cost of borrowing. Fees may appear separately, and their treatment needs to follow the bank's reporting and the applicable rules.

Do not take the entire monthly payment and label it deductible interest. Identify interest and any reported deductible costs. Use the annual statement to check a completed year and the repayment schedule as a starting point for a new estimate.

What could the deduction be worth?

A simplified example uses NOK 50,000 of deductible interest multiplied by the standard 2026 rate of 22 per cent, producing NOK 11,000. It assumes the deduction has full effect in the relevant calculation. It is not an estimate of any particular person's tax settlement.

Using 18.5 per cent gives NOK 9,250 for the same arithmetic. That rate applies to the defined action zone, not everyone living anywhere in northern Norway. Use the Tax Administration's rate information and the rules governing your tax location.

The tax deduction card uses estimates

The tax deduction card, or skattekort, determines withholding during the year. The Tax Administration enters information and estimates, but the card is not automatically updated whenever your debt, interest or circumstances change. Check whether its figures still fit.

An interest estimate that is too high can produce insufficient withholding and a later tax bill. An estimate that is too low can result in more being withheld during the year than necessary. The aim is accurate information, rather than the largest possible deduction.

Compare the tax return with annual statements

When the return for the relevant year is available, compare its pre-filled figures with annual statements. Norwegian banks normally report loans, interest and relevant costs, but pre-filling does not remove the need to check.

Start with the bank and loan number, then the amount and your share of the debt. If you changed banks, statements may come from both the former and new lender. Avoid adding a cost that has already been reported.

Joint loans: responsibility and allocation

Everyone sharing a loan needs to check the allocation. The Tax Administration distinguishes spouses and certain equivalent groups, who have greater freedom to allocate, from ordinary cohabitants and other co-borrowers. For the latter, equal allocation is the starting point unless another internal agreement applies.

The bank account used to pay does not alone determine who receives the interest deduction. Responsibility for the debt and correct allocation are central. Do not confuse ownership of the property with liability for its loan without reading the agreement.

When allocation changes, the people concerned must ensure that the total remains 100 per cent. One person cannot increase their share while leaving the other's figures unchanged. The tax deduction card and the return need separate checks.

Co-borrower or guarantor?

Read the loan agreement if your role is uncertain. A co-borrower is jointly responsible for the loan. A guarantor guarantees it and is not automatically treated as an ordinary borrower from the outset.

The Tax Administration says a guarantor does not obtain an interest deduction before potentially taking over liability, and then only for interest accruing after that point. The actual agreement matters more than a family's informal description of someone “helping out”.

Shared debt in a housing cooperative or co-ownership

A personal mortgage may not be the whole picture. If the property has shared debt, information about your share of debt and interest can come from the housing cooperative or co-ownership. Find the annual statement from its administrator or reporting body.

Official guidance places this information under housing and assets, with separate entries for debt and the share of costs. Compare the documents with the correct part of the return. Do not enter the entire common-cost payment as interest.

Refinancing and multiple statements

Refinancing can involve a move between banks or several loan numbers. Make a simple timeline showing when the old loan ended and the new one began. This helps you check each statement without counting one cost twice.

The Tax Administration describes deductions for certain refinancing costs, distinguishing them from costs of buying and selling property. The bank reports relevant amounts paid to it. Other possible costs need separate checking against documentation and the rules.

BSU is a separate tax benefit

Searches for rentefradrag boliglån often lead to bsu skattefradrag. Keep the schemes separate. Mortgage interest concerns debt costs, while BSU is a housing savings scheme with its own conditions for a direct deduction from tax.

For 2026, the Tax Administration specifies a 10 per cent BSU deduction on qualifying deposits, with an annual deposit limit of NOK 27,500. This does not mean a homeowner with a mortgage automatically receives both benefits. BSU conditions include age and residential property ownership at year-end.

Foreign loans and PAYE on salary

With a foreign loan or tax liability in more than one country, the standard domestic explanation may be incomplete. Gather the loan agreement, annual figures and information about who is liable, then ask the Tax Administration which rules apply.

If you are in the PAYE on salary scheme, known as kildeskatt på lønn, ordinary deductions cannot be claimed within that scheme. The Tax Administration provides a comparison with general tax rules. A potential interest deduction alone is not enough to determine which scheme best fits the whole situation.

Where to ask for help

Start with the bank when the question concerns a reported amount and the Tax Administration when it concerns a tax rule. If you want paid assistance, describe the task precisely: reconciling statements, allocating a joint loan or reviewing foreign circumstances.

Possible contacts can be found in the directories of finance and accounting firms in Oslo and finance and accounting firms in Kristiansand. Establish whether the firm works with private individuals and has experience with your issue.

NorgeGuide's rankings can help you find possible service contacts. Ask for a clear description of the service. Share necessary documents through an appropriate channel while retaining control of your own login.

Images and content blocks

Cover at the top: keys, a calculator and neutral papers on a table; no readable text, bank logos, account numbers or people.

After annual statements: a document folder and pen, without personal data.

After the calculation: a designed graphic showing 50,000 × 22% = 11,000, clearly labelled as a simplified example for the 2026 income year, not a promised payment.

After joint loans: a simple diagram showing two shares adding to 100%, without suggesting one allocation suits everyone.

Retain both tables as tables. No Google Maps block or screenshots of logged-in tax services are needed.

Official sources

Checked on 11 November 2026. Figures apply to the 2026 income year.

Norwegian Tax Administration: loans and interest.

Allocation of joint loans and interest.

Ordinary income rates for 2026.

Figures in the tax deduction card.

Viewing, changing and submitting a tax return.

Advance tax assessment for 2026, including BSU.

PAYE on salary.