B-skat and acontoskat: how tax is paid during the year

How the system fits together

The profit in your sole proprietorship is personal income: you pay 8% labour-market contribution (AM-bidrag) and then ordinary income tax on it. But the tax is collected provisionally — you enter your expected profit on the forskudsopgørelse (field 221), and the Tax Agency converts it into B-skat instalments. After year-end, everything is settled in the annual tax assessment.

The instalments: 10 per year

B-skat is paid in 10 equal instalments — every month except June and December. Each instalment falls due on the 1st of the month, with the 20th as the final day to pay on time. Every instalment covers both tax and AM-bidrag, and you pay via TastSelv or direct debit (Betalingsservice).

The forskudsopgørelse is your most important tool

If your actual profit misses what you registered, you end up with residual tax or excess tax. So adjust the forskudsopgørelse as soon as you can see the year turning out better or worse than expected — it can be changed at any time on skat.dk, and the remaining instalments are recalculated automatically.

That of course requires knowing what your profit actually is right now — one more reason to keep the bookkeeping current all year instead of once a year.

Your first year: the classic trap

The Tax Agency doesn't know your new business, so no B-skat instalments appear automatically when you start. If you do nothing, you pay zero tax on the business all of year one — and get the whole bill as residual tax with a surcharge the year after. Update the forskudsopgørelse as soon as you're up and running.

The tax return and annual assessment

As self-employed you must complete the extended tax return (oplysningsskema) with the business's result every year — the deadline is 1 July in the year after the income year. Then comes the annual assessment, and any residual tax is collected with a surcharge. The basis is your bookkeeping, so up-to-date accounts make the return a formality.

Numina keeps the numbers ready

Numina's bookkeepers and AI keep your books current, so you can always see your actual profit in the app — and adjust the forskudsopgørelse on real numbers instead of a gut feeling. We file your VAT automatically, and the figures for the tax return are ready when the deadline approaches.

Acontoskat: how your company pays tax during the year

The 22% Danish corporate tax isn't paid once a year but continuously, as acontoskat in two ordinary instalments. If the instalments miss the company's actual profit, it costs a surcharge — or ties up cash unnecessarily. Here are the rules and the dates.

The deadlines: 20 March and 20 November

Acontoskat is paid in two ordinary instalments due by 20 March and 20 November of the income year. Payment goes through the tax account (skattekontoen) in TastSelv Erhverv, and if a deadline falls on a weekend or public holiday, it moves to the next business day.

How the ordinary instalments are calculated

The Tax Agency sets the ordinary instalments at half of the average of the company's actual corporate tax over the last three income years. Newly founded companies are therefore typically not charged ordinary acontoskat in their first years — there's no history to calculate from. That doesn't make the tax free: it just arrives as one large bill later, unless you pay voluntarily.

Voluntary payments: track reality more closely

If the year is turning out better than the historical figures, you can pay voluntary acontoskat on top — at the March and November deadlines, and again by 1 February the following year. Pay in March and you're credited a small premium; pay in November or February and you instead pay a small surcharge. The rates follow interest levels and are set each year.

The maths is simple: residual corporate tax carries a percentage surcharge that is not deductible. If the cash is sitting in the account anyway, a voluntary payment is often the best "interest rate" the company can get.

Lower the instalments if the year disappoints

If profit is coming in below the historical years, you can conversely have the ordinary instalments reduced via TastSelv Erhverv. Be realistic — the Tax Agency can ask for documentation, and if you set the instalments too low you just end up with residual tax plus the surcharge anyway.

With Numina the basis is always ready

The voluntary-payment decision needs one number: the company's expected profit. With continuous bookkeeping at Numina you can see the year-to-date result in the app at any time — so you can judge before the March and November deadlines whether to adjust, instead of guessing.

The terms behind it, briefly explained

Finally a quick glossary of the terms from this article — brief and concrete, the way we explain them to our customers.

What is B-indkomst (untaxed income)?

B-indkomst is income paid out without tax withheld — e.g. freelance fees and profit in sole proprietorships. The recipient settles the tax themselves.

The tax is paid in B-tax instalments based on the forskudsopgørelse. If you receive B-income, update the preliminary assessment so the instalments fit — or face a tax bill.

What is a forskudsopgørelse (preliminary tax assessment)?

The forskudsopgørelse is your tax budget for the coming year with the Tax Agency: it sets the withholding rate and B-tax instalments before the year starts.

As self-employed you should update it whenever your profit expectation changes — that's how you avoid big tax bills or paying too much during the year.

What is an årsopgørelse (annual tax assessment)?

The årsopgørelse is the Tax Agency's final statement of your tax for an income year — your income, your deductions, and whether you paid too much or too little.

It opens in March and is often just a check for employees. As self-employed you must report the business's result yourself via the tax return (deadline 1 July) before your assessment is correct. Overpaid tax is refunded automatically; underpaid tax must be paid.

What is restskat (underpaid tax)?

Restskat is the tax you still owe once the year is settled — because too little was paid during the year compared to your actual income.

Pay it before New Year and it costs the least; wait, and interest and later a fixed surcharge are added. Smaller amounts are rolled into next year's preliminary tax automatically. Update your preliminary assessment when income changes — that is how you avoid the surprise.

What is an oplysningsskema (tax return)?

The oplysningsskema (formerly selvangivelsen) is the annual reporting of your income to the Tax Agency. Self-employed report the business result here — typically by 1 July.

The figures come from the annual accounts, so up-to-date bookkeeping makes the tax return trivial. Numina can file it as an add-on.

What is selskabsskat (corporate tax)?

Selskabsskat is the tax on company profits — 22% in Denmark. It's paid by the company before dividends can be distributed to the owners.

Corporate tax is prepaid as acontoskat in March and November. Salary to the owner is deductible for the company and thus reduces the corporate tax.

What is personfradrag (the personal allowance)?

The personfradrag is the amount everyone can earn tax-free each year before income tax kicks in. In 2026 it is DKK 54,100.

The allowance is applied automatically through your preliminary tax. Any unused part transfers to your spouse. The 8% labour-market contribution is still paid on all salary income — even below the allowance.

What is topskat (top-bracket tax)?

Topskat is an extra 7.5% tax on personal income above the top-tax threshold — DKK 777,900 after labour-market contribution in 2026.

From 2026 the old top tax is split in three tiers: middle tax (7.5% above DKK 641,200), top tax (a further 7.5% above DKK 777,900) and top-top tax (a further 5% above DKK 2,592,700). For owner-managers the tiers often make a mix of salary and dividends attractive.