Claim Against Microsoft

Frequently Asked Questions

About the claim

This website has been created to inform potential class members about a proposed opt-out collective claim brought by Alexander Wolfson against Microsoft in relation to its alleged anti-competitive conduct in the software licensing market.


This website will be updated regularly throughout the claim.

The claim is against Microsoft Corporation, Microsoft Ireland Operations Limited and Microsoft Limited. Together, these entities are referred to as “Microsoft”.

The claim alleges that any public or private organisation in the UK that purchased certain software licences (including for Microsoft Office and Windows) was overcharged as a result of Microsoft’s market practices.

The proposed class representative is Alexander Wolfson, who is bringing the claim on behalf of the proposed class members.


Alexander Wolfson is a highly experienced barrister of more than 25 years standing. He served as a Senior Prosecutor for the CPS for over 16 years, adeptly prosecuting many complex and high-pressure criminal trials. Mr Wolfson returned to private practice in 2023, undertaking both prosecution and defence work as required. Combining his strong sense of civic duty, an unflinching belief in due process and the law and his proven ability to manage largescale litigation, Mr Wolfson is well placed to represent the class members and ensure that Microsoft is properly held to account.

Stewarts are the lawyers providing legal advice and support to Mr Wolfson.

Stewarts is the UK’s largest litigation-only law firm, well known for its expertise in competition litigation. The firm is top-ranked in both The Legal 500 and Chambers, the leading guides to the legal profession in the UK and comprises some of the UK’s leading litigation lawyers. The team at Stewarts has litigated some of the largest and most complex competition damages claims in the English Courts to date and has an impressive track record in successfully representing clients in the Competition Appeal Tribunal, High Court, Court of Appeal and Supreme Court.

The team is further supported by top flight competition counsel: Jon Turner KC, Rob Williams KC and Luke Kelly of Monckton Chambers and Christopher Brown of Matrix Chambers.

In addition, Mr Wolfson has instructed a team of experts who will be responsible for providing evidence in relation to the impact of Microsoft’s alleged breaches of competition law and the losses suffered by class members as a result.

The claim is fully funded by Harbour.

About collective claims

Opt-out collective proceedings are a special form of court proceedings that enable a class representative to bring a claim on behalf of a defined class of persons in the UK affected by an infringement of competition law.

This means that if your organisation fits within the class definition you will automatically be included in the claim and will be bound by any judgment or settlement unless you choose to opt-out of the proceedings. More information regarding opting out of the claim will be posted to this website at a later date.

The Competition Appeal Tribunal is a specialist court situated in London that covers the whole of the UK, which is dedicated to cases involving competition law issues. The Competition Appeal Tribunal publishes its rules and guidance, together with information about what it does and details of its ongoing cases, on its website at www.catribunal.org.uk.

Before the claim can proceed, the class representative must obtain the permission of the Competition Appeal Tribunal. This process is known as obtaining a Collective Proceedings Order (“CPO”). The Competition Appeal Tribunal will then determine whether (1) it is suitable for the class representative to represent the class; and (2) the claims are appropriate to proceed on a collective basis. Once the CPO is granted, the class representative will be able to bring the claim to trial.

A class representative is responsible for conducting the claim on behalf of the class members, including evaluating any offer of settlement that the defendant(s) may make and deciding whether to present that offer to the Competition Appeal Tribunal for their approval. The class representative will be responsible for communicating with the class and issuing formal notices to the class members. 

The class representative will communicate with the class via updates and announcements posted on this website and through email correspondence and press notices.

Class membership

These proposed proceedings are being brought on an opt-out basis on behalf of any public or private organisation domiciled in the UK that purchased certain software licences (including for Microsoft Office and Windows), referred to as the ‘class members’. More information on the eligible class members will be posted to this website at a later date.

There is no need to do anything to participate in this claim. As these are opt-out proceedings, organisations that fall within the class definition are automatically included in the claim. However, you can register your interest in the claim and sign up for updates here.

Your organisation does not need to pay anything towards the costs of this claim. Mr Wolfson has secured funding from this claim from a litigation funder, Harbour.

Harbour have committed to funding all legal costs associated with bringing this claim. Harbour is a trusted advisor and provider of funding to law firms and claimants, supporting them in high-value commercial disputes all over the world. Harbour is renowned for its litigation experience, finance experts and has a deep understanding of the complexities involved in complex litigation.

No. You will not be at any risk of having to pay any of Microsoft’s costs should the claim not be successful.

Further information

Please click here if you would like to receive updates on the progress of this claim. Updates will also be regularly posted on this website.

For enquiries regarding the claim, please send an email to enquiries@microsoftclaim.co.uk or click on ‘Contact’ at the top of this page and fill out the contact form.