Aconto corporate tax 2026 — how to optimise your instalments
Aconto corporate tax is the prepayment of corporate tax that the Danish Tax Agency requires from Danish limited companies. For 2026 the corporate tax rate is 22% and aconto instalments are due in March and November. Incorrect amounts — either too small or too large — cost you either residual tax surcharge or liquidity that could have been invested in the business.
The three aconto instalments
Section 29A of the Corporate Tax Act requires two ordinary instalments: 1st by March 20, 2nd by November 20. Each covers half of the tax agency's calculated aconto, based on the last annual assessment. A voluntary 3rd payment per §29B can be made by February 1 of the following year, typically used when projected tax exceeds the assigned aconto.
What is the residual tax surcharge?
If final tax exceeds aconto payments, a surcharge applies to the difference. For 2025 the surcharge was 4.5%; for 2026 it's projected at 4.8–5.1%. If by Christmas you can see that your profit will be significantly higher than the aconto basis, the voluntary 3rd payment almost always pays off.
Calculating the optimal payment
Simple rule: expected annual tax = expected annual profit × 22%. If you expect DKK 800,000 in profit, expected tax is DKK 176,000. The agency's ordinary aconto covers this if based on a similar profit last year. But what if you're growing 30%? Then the ordinary aconto is DKK 50,000 too low, and the voluntary 3rd payment compensates. Freja in AdvisorGate calculates this automatically from your real-time results and forecasts.
Exceptions — new companies and tax-exempt income
Newly started companies in their first full fiscal year aren't automatically required to pay aconto — there's no basis for calculation. In practice, you handle all tax as residual the following autumn, unless you voluntarily pay aconto per §29B. For companies with tax-exempt income (e.g. holding companies only receiving exempt dividends), aconto is DKK 0.
Sole proprietorships and VSO
This guide applies to limited companies (A/S and ApS). For sole proprietorships using the business scheme (VSO), rules differ: B-tax, AM-bidrag and provisional business tax are collected via B-tax instalments, typically 10 times per year. Freja supports both forms, but VSO optimisation focuses on private withdrawals vs. retained business savings.
Three instalments, three optimisation opportunities
Aconto corporate tax looks like a simple admin task but offers major savings — especially for fast-growing companies. Paying the right amount on time saves 4.8–5.1% in surcharge, and avoiding overpayment preserves liquidity. Freja monitors your expected year-end result and automatically suggests aconto adjustments.
Ofte stillede sporgsmol
What if I overpay aconto?
Excess is refunded at the annual assessment with a small interest credit (~0.3%). Rarely a good trade — money is locked for 12-18 months. Only overpay if highly uncertain about your result and wanting to avoid the 4.8–5.1% surcharge.
Is the voluntary 3rd instalment really voluntary?
Legally yes — you aren't penalised for skipping it. Economically, it's often profitable because 4.8–5.1% surcharge on large residual tax quickly exceeds alternative returns over 2 months. Freja calculates whether the voluntary payment makes sense for you.
Can I apply for deferment of aconto?
Yes. With serious liquidity problems, apply to the tax agency per Opkrævningsloven §15. The application must be timely (by due date) with a strong justification. Freja's crisis protocol tracks this automatically.
Try Freja for free
Complete guide to aconto corporate tax per Selskabsskatteloven §29A and §29B. Learn when to pay, how to avoid residual tax surcharge, and how Freja calculates the optimal amount.
Get started