A UK data breach claim could be coming. Register your interest and if it does, you’ll be the first to know.
No-win, no-fee
Overview
The Irish Council for Civil Liberties (ICCL) is taking on Microsoft, accusing the tech giant of breaking GDPR rules. The issue? A behind-the-scenes process called real-time bidding, where your personal information is shared with advertisers the moment you visit a website.
The ICCL says Microsoft is collecting and sharing more data than it should – and not always with proper consent. If the courts agree, it could open the door to claims here in the UK.
If a claim is launched here at home, you could be entitled to compensation. We’re monitoring the case closely and will help you check your eligibility if the time comes. And, if you qualify, we’ll connect you with a trusted UK law firm.
Microsoft data breach claim – At a glance
What do we know about the Microsoft data breach claim?
Who is eligible to join the Microsoft data breach claim?
We’re monitoring the case closely. Register for updates and we’ll help you check your eligibility if the time comes.
“People’s intimate secrets such as their relationship, work and financial status are broadcast by Microsoft into the Real-Time Bidding advertising system. That system is a black hole of data open to any malicious actor and represents a huge data breach of millions of people’s information”.
How Join the Claim works
Register for updates and we’ll let you know as soon as more information becomes available.
If a UK claim is launched, we’ll invite you to check your eligibility and update you on the next steps.
Sign up to find out more about other claims you could be eligible to join.
Latest updates on the Microsoft data breach claim
July 2025
Join the Claim opens registration to those interested in finding out more about any future UK claim.
May 2025
The ICCL applies to High Court to begin proceedings against Microsoft. Proceedings are then formally launched in Ireland.
May 2018
GDPR comes into force.
We’ll provide more updates on the Microsoft data breach as they occur.
Can you join the Microsoft data breach claim?
Register for updates on the Microsoft data misuse claim.
It will only take a few minutes and there’s no obligation to proceed.
Frequently asked questions
This claim is about how Microsoft’s online advertising system handles your personal data. The ICCL alleges that Microsoft is breaching GDPR rules by sharing sensitive information, like your location, interests, or even political views, with hundreds of advertisers without your clear consent. They argue this happens through a process called real-time bidding, and that it’s putting users’ privacy at risk.
It’s a system where ads are bought in milliseconds based on your real-time data—like browsing history or location—with no clear path of consent or control over what happens after it’s shared.
Microsoft’s RTB system covers users of Windows, Xbox, Edge, web‑based Office, and apps using Xandr data. If UK-based users have been caught in this system, a successful Irish case could pave the way for UK claims.
At this stage, the focus is on injunctive relief (stopping the privacy breaches). Any compensation will depend on if and when a UK claim is launched.
We’re keeping a close eye on this. If a UK version is filed, we’ll notify you immediately, help you check eligibility, and put you in touch with a trusted law firm.
No. There’s nothing to lose by registering with us and finding out if you’re eligible if a claim is launched.
In the UK, if a group of people have experienced loss, or otherwise been harmed by an organisation’s law breaking, they can come together to fight for justice. Levelling the playing field when standing up to big businesses, group actions prove that there is strength in numbers. At Join the Claim, we bring consumers and law firms together to ensure these group actions are as powerful as possible.
A no-win, no-fee agreement means you don’t pay your solicitor’s legal fees if your claim is unsuccessful. This makes it easier and more affordable to take part in group litigation. However, T&Cs apply.
Want the full picture, including what to check before signing? Read our complete guide to no win, no fee agreements here.
We connect consumers with their legal dream teams to ensure they get the compensation and support they deserve.
Join the Claim is not a law firm. We connect individuals with top law firms for group action claims, and our service is free to use. While we may receive a fee from the law firms we introduce you to, this will not affect your costs or compensation. We are not responsible for the advice or services provided by these firms. Please note, nothing on this website is legal advice, and while we check claim eligibility, we cannot guarantee a law firm will accept a case.
Join the Claim is a registered trading name of Big on Media ltd. Big on Media is registered in the United Kingdom under licence number 09878028 with its registered office located at Big on Media, 6 Sunderland Street, Tickhill, Doncaster, DN11 9QJ
© Join the Claim All Rights Reserved | 2025
