A tax ruling ended an 11 year fight over which country can tax 2 Orsted offshore wind farms in the UK, after Denmark claimed 1.03 billion dollars

The Orsted tax ruling that ends a UK offshore wind double taxation dispute

An Orsted tax ruling on 2 UK offshore wind farms has closed an 11 year fight with Denmark over double taxation, a company paying tax on the same income twice. On September 10, 2026, the Danish Tax Agency and the UK tax authority, HM Revenue and Customs, told Orsted that an advisory commission, a panel set up to decide exactly this kind of cross border dispute, had issued its final opinion on which country can tax profits from Hornsea 1 and Walney Extension, 2 offshore wind farms. The commission found the projects have a genuine legal and economic purpose and are primarily taxable where they physically sit and generate power, the UK, not Denmark.

Why the dispute took 11 years to resolve

Orsted first asked the 2 tax agencies to settle the question in 2015. When Denmark and the UK could not agree between themselves, the case moved in 2023 to an advisory commission set up under the EU Arbitration Convention, a European Union process built to settle cross border tax disputes like this one. The final ruling landed in 2026, 11 years after Orsted first asked and 8 years after the case reached formal arbitration, both counted here from the dates Orsted, Kalkine Media and Reuters each report.

The finding behind the ruling

Danish tax authorities had claimed 6.6 billion Danish kroner, about 1.03 billion dollars, in taxes and interest on the 2 wind farms, according to Reuters. In the press release announcing the ruling, Orsted describes the actual financial effect very differently, calling it a minor upward adjustment to its Danish tax position, already fully covered by money set aside for exactly this kind of uncertain tax question, and one expected to be offset over time by lower tax owed in the UK. That gap, a claim near 1.03 billion dollars against an unquantified minor adjustment, is the real outcome of this case, not the number Denmark once sought.

The wind farms behind the dispute

Hornsea 1 is rated at 1.2 gigawatts, was the first offshore wind farm in the world to pass 1 gigawatt of capacity, and powers over 1 million UK homes with 174 turbines in the North Sea. Walney Extension, in the Irish Sea off Barrow in Furness, is rated at 659 megawatts, powers nearly 600,000 homes, and is owned 50% by Orsted alongside AIP Management and PFA. Orsted operates 11 gigawatts of offshore wind capacity worldwide in total, with another 7.2 gigawatts under construction.

What Orsted does next

Orsted says it will now apply the same reasoning the commission used in this case to try to settle similar tax questions on other projects, so this ruling could shape how the company handles cross border tax exposure well beyond Hornsea 1 and Walney Extension.