Opt-out collective actions allow a single case to be brought on behalf of a large group of consumers – all of who may have been affected in the same way.
Typically, these cases involve allegations that companies breached competition law. For example by overcharging consumers, abusing a dominant market position, or entering agreements that restrict competition.
And opt-out claims are powerful. Because, when millions of people are affected by the same issue, the individual losses may be small, but collectively they can amount to very significant sums.
How do opt-out claims work?
Opt-out claims are designed to make it possible to pursue those losses collectively.
Instead of every consumer bringing their own claim, a single case can be brought on behalf of the entire group.
However, despite the growing number of opt-out cases in the UK, public awareness of them remains low. Many people only hear about these proceedings years later, if at all.
By explaining how the system works and tracking major claims as they develop, Join the Claim is helping consumers understand when a case may affect them and what it could mean in practice.
Why understanding the legal process matters
Opt-out collective actions are designed to improve access to justice, particularly where individual losses would be too small to justify bringing a claim alone.
But the process can take several years to reach a conclusion, and the legal stages involved are not always easy to follow from the outside. As a result, many people are unaware that a case is progressing on their behalf until a compensation scheme opens — if they hear about it at all.
Understanding how these cases unfold helps make the process clearer. And, while each claim is different, most follow a broadly similar path through the courts.
The key stages of an opt-out collective action
1. A class representative brings the claim
The process begins when a proposed class representative files a claim with the Competition Appeal Tribunal (CAT).
The class representative brings the case on behalf of a wider group of people who may have been affected in the same way.
This group is known as the “class” and typically includes all consumers who bought a particular product or service during a defined period.
The representative may be a consumer campaigner, organisation or another individual who is willing to act on behalf of the group.
At this early stage, the Tribunal will also consider issues such as whether the representative is suitable for the role and whether the claim has appropriate funding arrangements.
2. The Tribunal decides whether the case can proceed
Before a claim can move forward, the Tribunal must decide whether it is suitable to proceed as a collective action.
This stage is known as certification, and if successful the Tribunal grants what is called a Collective Proceedings Order (CPO).
When deciding whether to certify the case, the Tribunal considers factors such as whether the claims raise common issues across the class and whether the proposed representative can fairly and adequately represent the group.
Certification is often the most heavily contested stage of the process.
3. The class is defined and consumers are notified
If the case is certified, the Tribunal sets out how potential class members will be informed.
- Affected UK consumers tend to be automatically included in the claim unless they actively choose to opt out. This means they do not need to sign up at the start of the case in order to be represented.
- Affected consumers who live outside the UK are usually required to opt in if they want to take part.
Notification can take several forms. The Tribunal may require notices to be published on dedicated case websites, in national newspapers, on digital platforms or through other media channels. These notices explain what the case concerns, who may be affected and what rights consumers have in relation to the proceedings.
In practice, many opt-out cases progress for several years before reaching a conclusion. During that time, awareness of the proceedings can remain limited, particularly where the affected group is very large.
This is one of the gaps Join the Claim aims to address. By raising awareness earlier in the process, we help ensure that when official notices are issued — or compensation schemes eventually open — people are not encountering the case for the first time.
4. The case moves into the litigation phase
After certification, the case enters the main litigation stage.
This part of the process may involve the exchange of documents, expert economic evidence and detailed legal argument about whether competition law has been breached, and whether the class suffered a loss as a result.
Because these cases often involve complex economic analysis, the litigation phase can last several years.
5. A judgment or settlement is reached
The case may end either with a Tribunal judgment or through an agreed settlement between the parties.
If a settlement is reached, the Competition Appeal Tribunal must approve it to ensure that it is fair and reasonable for the class as a whole. At this stage the total compensation package is determined.
However, even after a judgment or settlement decision, the case may not yet be finished. Parties sometimes challenge Tribunal decisions through the appeals process.
As a result, opt-out collective actions can take many years to reach a final outcome before any compensation is distributed.
6. A compensation scheme is approved
If the case succeeds, the Tribunal approves a distribution plan and a claims administrator is appointed to manage the process.
Eligible consumers are then invited to come forward and claim their share of the compensation.
This final stage is where people who were affected may ultimately receive payment.
Learn more about opt-out claims
Opt-out collective actions can take many years to progress from filing to compensation.
Understanding the legal process helps explain why these cases unfold the way they do and why awareness is so important.
If you would like to find out more, you can read our full guide to opt-out collective actions.
Closing the awareness gap
Opt-out collective actions were designed to level the playing field between consumers and large corporations.
But the system only works if people know the cases exist.
At Join the Claim, we track major opt-out collective actions, explain what they mean in plain English, and point people to official sources so they can check whether they might be affected.
While our list is not exhaustive, we are continually adding new cases as they emerge.
Join the Claim is not a law firm. We raise awareness of group actions and signpost consumers to official claim websites and trusted sources. For opt-out claims, we are not involved in running the litigation or handling claims. This information is for general guidance only and does not constitute legal advice.
