Poland enacts 60% fuel windfall tax with retrospective March 2026 coverage

Who pays and how the base works

The Act covers businesses producing liquid fuels in Poland or trading them under a licence for foreign trade in liquid fuels, whether operating themselves or through another entity. Heating oils are excluded from the statutory liquid-fuel definition. The base is actual fuel-sale revenue exceeding hypothetical revenue calculated from actual acquisition or production costs and a reference margin.^[1]

The reference margin is the taxpayer’s average 2025 fuel-sales margin increased by 20%, with a 2% minimum. Businesses without relevant 2025 activity also use 2%. Related-party revenue and cost transactions must follow the arm’s-length principle. The Act contains specific rules for hedging results and shared-cost allocation, excludes unrealised valuation and exchange-rate items, and requires legal predecessors to be taken into account.^[1]

A 60% rate, with a cap for non-producers

Article 8 sets the rate at 60% of the calculated excess. For taxpayers that do not produce liquid fuels, the tax is capped at 50% of the relevant income or net profit attributable proportionately to the tax year. For corporate income-tax taxpayers, the income measure is income other than capital gains before reductions and deductions, including carried-forward losses. The cap is distinct from a 50% tax rate.^[1]

Payments, deductibility and linked excise powers

Monthly advances are cumulative and payable by the 25th day of the following month. The first covers 1 March to 31 October 2026, making November the first payment month. The electronic return and final settlement are due by 31 December 2027. Article 13 inserts article 38zb into the Corporate Income Tax Act of 15 February 1992, expressly denying a deduction for this windfall tax; article 12 makes the corresponding personal income-tax amendment.^[1]

The Act’s general commencement is 1 November 2026, but article 11’s authority to reduce specified fuel excise rates took effect on 2 October. Multinational refining and licensed fuel-trading groups therefore need to assess earlier 2026 transactions as well as upcoming payments, including their 2025 reference data, group pricing and the non-deductible tax cost. Separate regulations issued on 2 October exercise the excise power and introduce temporary fuel VAT relief.^[1][2]