Microsoft given until 25 July to respond to UK cloud licensing legal claim

Microsoft has until 25 July 2025 to respond to a £2bn legal claim, filed on behalf of thousands of UK businesses that were allegedly overcharged for running its Windows server software in its competitors’ cloud environments.

The Competition Appeal Tribunal (CAT) set the deadline while confirming that it has ordered a court hearing to take place on 11 December 2025 to can decide if a collective proceedings order (CPO) for the matter should be granted.

The CPO is a legal mechanism that allows a collective action involving multiple claimants with similar issues to band together in a single legal action against an entity on anti-competition grounds.

As previously reported by Computer Weekly in December 2024, the legal action against Microsoft is being overseen by competition lawyer Maria Luisa Stasi and her legal team at complex disputes resolution firm Scott+Scott.

“The hearing in December 2025 will determine whether the tribunal grants a collective proceedings order, certifying the claim and paving the way for it to proceed to full trial,” said Stasi’s team in a statement.  

“The tribunal additionally ordered that Microsoft must file their response to the legal claim by 25 July 2025, adding that Stasi will file her reply to Microsoft’s response by 10 October 2025.”

According to Stasi’s updated claim, the UK firms that have so far joined the action could be collectively owed around £2bn in compensation because of Microsoft’s controversial cloud licensing tactics.

Microsoft is trying to force customers into using its cloud computing service, Azure, and restricting competition in the sector

At the time of the legal action’s launch, Stasi said the lawsuit was designed to “challenge Microsoft’s anti-competitive behaviour” for the benefit of all UK businesses and organisations that have found themselves paying more to access the same software just because they choose to run it in someone else’s cloud.

“Put simply, Microsoft is punishing UK businesses and organisations for using Google, Amazon and Alibaba for cloud computing by forcing them to pay more money for Windows Server,” said Stasi. “By doing so, Microsoft is trying to force customers into using its cloud computing service, Azure, and restricting competition in the sector.”

Computer Weekly contacted Microsoft for comment on the latest development in the case, but had not received a response at the time of writing.

Microsoft’s cloud licensing practices have been the subject of scrutiny by competition regulators and trade associations across the UK and Europe for several years now.

During its probe into anti-competitive behaviour within the UK cloud market, the UK Competition and Markets Authority (CMA) singled out Microsoft’s decision to charge customers more for running its software in other people’s clouds as a point of contention.

Rival suppliers are also gunning for Microsoft over this matter, with details emerging in September 2024 that cloud giant Google had filed a complaint with the European Commission over its competitor’s cloud licensing practices.

At the time of the filing, the internet search giant’s public cloud arm claimed Microsoft’s behaviour risks harming customers and infringes European Union law. It also accused Microsoft of “leveraging its software monopoly” to lock customers into its Azure public cloud platform.