EU court strikes down Hungary carbon tax on emissions allowances

Hungary’s attempt to tax free carbon allowances ran into the European Union’s top court, which said the measure stripped the permits of the value Brussels intended them to have and could not stand under EU law. The ruling, delivered on 16 April 2026 in Case C-519/24, Nitrogénművek, is more than a narrow win for one fertilizer producer. It is a direct test of how far member states can go when they try to raise revenue through climate policy without breaking the rules of the EU emissions-trading system.

The tax was imposed in 2023, during the state of emergency declared by Hungarian authorities after the war in Ukraine. It targeted installations that received significant free allowances under the EU ETS, a group that includes cement, fertilizer, glass, steel and chemical plants. One verified account says operators emitting more than 25,000 tons of CO2e a year and receiving at least half of their allowances for free were caught by the regime. The levy was first proposed at 40 euros per ton and later cut to 36 euros per ton, a charge meant to generate revenue while offsetting emissions-related costs for the state.

The court said the Hungarian law neutralised the compensatory effect of free CO2 allowances and was contrary to the objectives of the EU emissions-trading directive, although the Veszprémi Törvényszék must still verify the underlying dispute. The case was referred from Veszprém on 8 July 2024 and lodged at the Court of Justice on 29 July 2024. Nitrogénművek Vegyipari Zrt. had already filed a constitutional complaint on 15 January 2024 against the carbon-dioxide quota tax and a related transactional fee, signalling how quickly the measure had become a legal and commercial flashpoint.

The decision matters because the EU carbon market depends on market signals, not political improvisation. Free allowances are meant to soften the blow for exposed industries while still rewarding investment in cleaner production. By taxing those permits, Hungary effectively cut into that incentive structure, a move the court said was inconsistent with bloc law. For energy-intensive companies across Europe, the ruling reinforces a basic constraint: national climate taxes must fit the EU framework, even when governments want fast cash.

The judgment also lands in a broader political fight with Viktor Orban’s government, which has repeatedly clashed with EU institutions and defied court rulings before. That history raises the stakes for implementation in Hungary, where the TISZA party of Peter Magyar has said little publicly so far and is aiming to form a cabinet by mid-May. For Brussels, the ruling is another reminder that the rule of law now runs through the carbon market as much as through the courts.