CO2 tax on commercial fishing, ferry operation and aviation

Everyone who buys fuel will now get an invoice stating the new CO2 tax. You may claim a partial refund of th CO2 tax until 2029. But from 2030, you will have to pay the full CO2 tax.

It's still possible to get exemptions from energy tax, NOx tax, and sulphur tax on fuel.

The CO2 tax will be introduced gradually prior to 2029.

This means that in 2025, for example, your refund will be 53.33% of the CO2 tax stated in your invoice.

Large commercial fishing vessels (5 GT or more) are subject to CO2 tax on fuel as of 1 January 2025 and gradually introduced towards 2030.

On 1 January 2026, a new act took effect meaning that this tax was temporarily put on hold for 2025. The CO2 tax on commercial fishing has likewise been put on hold for 2026, 20207 and 2028. It will be reintroduced on commercial fishing from 2029.

In 2025, commercial fishing operators could request a partial refund of the CO2 tax of 53.33%. The new act that was introduced on 1 January 2026 has put the tax on hold for commercial fishing. This means that commercial fishing operators can request a refund of the difference between the partial refund and the complete CO2 tax on invoicing of fuel for 2025.

It's still possible to be exempt from paying energy tax, NOx tax and sulphur tax on fuel for fishing vessels.

The new act that was introduced 1 January 2026 means that the CO2 tax on commercial fishing is suspended.

This means that you can get fuel without having to pay the CO2 tax if you have an exemption authorisation.

The CO2 tax will be gradually introduced prior to 2030.

Commercial fishing will be subject to the CO2 tax from 1 January 2029.

As a result, you will be able to see the new CO2 tax on your invoice when you buy fuel from 2029. You may claim a partial refund of the CO2 tax in 2029.

As of 2030, the full CO2 tax is payable.

You may still be able to obtain an exemption from having to pay energy tax, NOx tax and sulphur tax on the fuel.

* From 1 January 2026, you can request a refund of the difference between the partial refund and the full CO2 tax on invoicing of fuel for 2025.

As a business subject to VAT, you have to use the fields for refund available in your VAT return. If, for example, you want a refund of the CO2 tax, you have to write the actual refund (the amount) in the field CO2-afgift (CO2 tax) in your VAT return.

This means that refund filing deadlines are the same as your normal VAT filing deadlines.

As a business, you're responsible for calculating and stating the correct amount to be refunded.

If you don't have a CVR number or a VAT (SE) number as a non-Danish business, you have to register your business first.

You do so via form 40.112 – Registration of non-Danish Company.

In field 14, you state that the reason for your registration is that your business needs a VAT number to apply for an authorised exemption.

When you have a CVR or VAT number, you complete and submit an exemption form to be refunded for your CO2 tax. You do so via form 23.024 - Authorisation for tax exceptions and/or tax refunds on fuel for commercial fishing, domestic ferry operations and domestic aviation.

When you have been granted exemption, you can apply for reimbursement via form 23.004 Request for refund of tax on commercial fuel for commercial shipping, domestic ferry operation and domestic aviation.

The Tax Agency will process your form once you submit it.

All fishing vessels are subject to CO₂ duty on fuel

The CO2 tax for fishing applies to both domestic and non-Danish fishing. As an oil company, you must therefore always charge CO2 tax on the invoice when delivering fuel to fishing vessels, where the delivery takes place within Danish land or sea territory within the Danish 12-nautical-mile limit.

This also means that CO2 tax must always be charged when fuel is delivered in Denmark to non-Danish fishing vessels.

CO2 tax rates

The new CO2 tax rates on fuel are set out on skm.dk in the CO2-afgiftsloven (Act on CO2 tax).

As an oil supplier, you must invoice fishing vessels based on the applicable CO2 tax rate for the year, as shown in the rate overview. The CO 2 tax must also be clearly stated on the invoice issued to the fishing vessel.

Exemption from energy tax, NOx tax and sulphur tax

As an oil company, you may continue to supply fuel to fishing vessels over 5 GT (gross tonnage) without charging energy tax, NOx tax or sulphur tax.

If these conditions are met, fuel may be supplied tax-free when fishing vessels refuel themselves from a self-service facility directly into the propulsion tank. It's not a requirement that the oil supplier is physically present during refueling.

A self-service facility is defined as being unmanned. The vessel typically has a card for the self-service facility, which is used during refueling.

Exemption authorisations

The existing exemption authorisation continues to apply for energy tax, NOx tax and sulphur tax.

The CO2 tax is not covered by the exemption from 1 January 2025.

As a result, all parties that currently hold an authorisation to purchase fuel and lubricating oil without excise duties must be issued with a new authorisation by the Danish Tax Agency. This is expected to take place early in 2025.

The new authorisation will apply retroactively from 1 January 2025. This means that from 1 January 2025, the oil supplier may continue to supply fuel and lubricating oil exclusive of energy duty, NOx duty and sulphur duty, but inclusive of CO₂ duty, to fishing vessels that were covered by an exemption authorisation before 1 January 2025.

With effect from 1 January 2025, fishing vessels will also be able to obtain an authorisation for reimbursement of energy duty for which they have received an invoice.

Please read more in Danish here:

Our legal guide section E.A.4.6.1.7 Calculation of reimbursement (Opgørelse af godtgørelse) - info.skat.dk. Section  Partial refund of CO2 tax in the period 2025-2029 (”Delvis godtgørelse af CO2-afgift i perioden 2025-2029").

The new rules on reimbursement of energy taxes and the CO2 tax are stated in Act no. 683 of 11 June 2024 and in Act no. 1489 o f10 December 2024.

The rules on suspension and gradual introduction of CO2 tax for commercial fishing are stated in Act no. 1782 of 29 December 2025

Energy tax: Our legal guide E.A.4.1.8. Afgiftsfritagelse og afgiftsgodtgørelse, Indhold - Fiskefartøjer 'Afgiftsfritagelse'

NOx tax: E.A.7.2.0.8 Afgiftsfritagelse og afgiftsgodtgørelse

Sulphor tax: E.A.7.11.8.1 Afgiftsfritagelse

You find the most recent versions of the acts at  skm.dk/skattelove. And you find our legal guide in Danish at skat.dk/juridiskvejledning.