Restskat in Denmark: What It Is, What It Costs, and How to Avoid It

Every March, Skattestyrelsen publishes your årsopgørelse, the settlement of your actual tax for the prior year versus what was withheld. If your withholding came up short, the difference is restskat.

For salaried employees at a single employer, it usually does not happen. The system works as designed: your employer withholds A-skat every month based on your skattekort, and the numbers roughly balance out.

Expats are different. The conditions that produce restskat (income from multiple sources, mid-year arrivals, foreign bank interest, investment gains, rental income from abroad, and a forskudsopgørelse that was never quite right to begin with) are more common among people who moved here from somewhere else. If that is you, this article explains how the system works, what it costs, and how to cut the risk substantially.

What causes restskat

The årsopgørelse compares two numbers: what you owed in tax and what was actually collected. Restskat appears when the first number is bigger.

The most common triggers for expats:

Your forskudsopgørelse was inaccurate. This is the root cause for most people. The preliminary assessment sets your withholding rate. If it is based on stale or incomplete information: a salary estimate from when you arrived, a missing B-income figure, deductions you thought you would have but did not. The rate ends up too low.

Holiday pay from a previous job. Feriepenge is taxed in the year it is accrued, not when you receive it. Changing jobs can result in a lump-sum holiday pay payment that was not factored into your preliminary assessment.

Investment income. Share gains, dividends from foreign accounts, and interest from abroad all land as taxable income. If you did not declare them in your forskudsopgørelse, they were not accounted for in your withholding.

Using your primary tax card at two employers simultaneously. If both jobs apply your full personfradrag and employment deductions, you have effectively claimed each allowance twice. The årsopgørelse corrects that.

Property value tax on a newly purchased home. Ejendomsværdiskat does not appear in your preliminary assessment automatically when you buy during the year.

B-income: fees, freelance, consulting. Any income paid to you gross (without withholding) is entirely your responsibility to declare and pay tax on. Skattestyrelsen does not know about it until you tell them.

What restskat actually costs

The figures depend on when you pay relative to 1 July each year, which is the standard deadline for paying restskat on the prior year’s income. Confirm the exact deadline for your year in TastSelv or on skat.dk.

Before 1 July: daily interest only. From 1 January until the day you pay, interest accrues at an annual rate of 3.70%. Pay in mid-May and the extra cost is small. On a DKK 10,000 bill, roughly DKK 139.

After 1 July: flat surcharge. If you do not pay by the deadline, the daily interest stops and a flat 5.70% surcharge is applied instead. On DKK 10,000 that is DKK 570 added to what you owe. The total is then rolled into your tax for next year by reducing your personfradrag, so you pay it off gradually through higher monthly withholding, not as a single bill.

Above the instalment threshold. Amounts up to DKK 25,368 are covered by the instalment system (the surcharge rolls into next year’s tax). Anything above that threshold has to be paid directly, in three instalments in August, September, and October.

The practical takeaway: if you have restskat, paying it before 1 July is almost always the right call. The interest rate before the deadline is low. The surcharge after it is not.

How to check your årsopgørelse

Your årsopgørelse is published each year in March, typically around the third week of the month. You access it through TastSelv at skat.dk using MitID. This works from abroad; you do not need to be physically in Denmark.

When you log in, you will see whether you have a refund (overskydende skat) or a bill (restskat). Go through every line, not just the total. Skattestyrelsen pre-fills most information from your employer, your bank, and your pension provider, but not everything. You have to enter some deductions yourself.

Things worth checking manually:

Your transport deduction (kørselsfradrag), if you commute more than 24 km each way. Your union membership deduction. Interest paid on a Danish mortgage. Contributions to a private pension not connected to your employer. Any B-income you received gross.

The standard deadline to make corrections is 1 May. Skattestyrelsen occasionally extends this; check TastSelv for the current year’s deadline. If you spot a missing deduction that reduces your restskat, enter it before that date.

The real fix: keeping your forskudsopgørelse current

Paying restskat is the consequence. An inaccurate forskudsopgørelse is usually the cause. The way to stop it happening again is to treat your preliminary income assessment as something you actively maintain, not something Skattestyrelsen handles for you.

You can update your forskudsopgørelse at any point during the year through TastSelv. Changes take effect from the following month. Your employer is notified automatically and adjusts your withholding rate accordingly.

The situations that require an update:

• New job or significant salary increase
• Change in pension contributions
• Starting to earn B-income (freelance fees, consultancy income)
• Purchasing property in Denmark
• Receiving interest on foreign bank accounts
• Selling shares or funds at a gain
• Stopping work, going on leave, or changing hours significantly

For expats with B-income specifically: enter your expected gross B-income in your forskudsopgørelse. Skattestyrelsen will recalculate and, where possible, increase the withholding rate on your A-income to cover the additional tax. If the A-income withholding cannot absorb it all, you will receive giro transfer forms for the remainder.

The update takes a few minutes. Doing it when circumstances change beats discovering the shortfall the following March.

Voluntary early payment

If you know you are going to have restskat (because you have done the rough maths, or because your B-income landed in Q4 and was not in your preliminary assessment), you can pay it voluntarily before your årsopgørelse is even issued.

In TastSelv, under “Pay tax,” there is an option labelled “Voluntary payment of tax arrears” (Frivillig betaling af restskat). You enter the amount and pay directly. This stops interest accruing from the date you pay, rather than waiting until March when the årsopgørelse is issued.

This matters most when the amount is large or when you know the timing. If you earned a significant consulting fee in October that pushed you well above your forecast income, paying the estimated tax before year-end means you owe less interest when March comes.

It is not a commitment or an irreversible action. Skattestyrelsen will reconcile everything when the årsopgørelse is issued, and any overpayment is refunded automatically to your NemKonto.

If you have B-income: a separate path

B-income is income paid to you without tax being withheld at source: freelance fees, consulting income, income from a foreign employer while you are a Danish tax resident.

The cleanest approach is to enter expected B-income in your forskudsopgørelse so Skattestyrelsen can factor it into your withholding rate during the year. If the full amount cannot be absorbed through A-income withholding, you will pay the balance in ten monthly instalments (B-skat), with June and December payment-free.

If B-income arrives as a one-off lump sum and you did not have it in your preliminary assessment, you can pay the tax directly through TastSelv without waiting for the årsopgørelse. This avoids the restskat process entirely.

Either way, set aside approximately 45% of every gross B-income payment to cover AM-bidrag (8%) and income tax on the remainder.

If your B-income is significant or growing, or if you have income from multiple countries, this is the point at which professional advice earns its cost. The interaction between Danish tax on B-income and your home country’s system is not always obvious, and getting it wrong creates problems in two jurisdictions. A cross-border tax specialist familiar with both is worth consulting before the amount is large enough to complicate things.

What happens if you do nothing

Ignoring restskat does not make it go away. If you do not pay by 1 July, Skattestyrelsen adds the 5.70% flat surcharge and rolls the total into your tax for the following year by reducing your personal allowance. You pay more tax every month until the debt is cleared.

For amounts below the DKK 25,368 threshold, the system handles the collection automatically. But for larger amounts, Skattestyrelsen sends payment demands for the excess, due in August, September, and October. Ignoring those is a different kind of problem.

The more useful framing: if you cannot pay the full restskat by 1 July, paying part of it is still better than paying none. The daily interest only applies on the outstanding balance, so reducing that balance early reduces the final cost.

A note on leaving Denmark

If you leave Denmark during the year, you still have a tax liability for the period you were resident. Your årsopgørelse will be issued in March the following year and may show restskat. Log into TastSelv from abroad using MitID (it works internationally) and check. Make sure your NemKonto is active: that is where any refund goes, and where any direct debit for restskat payments would be drawn from.