A Guide to Group Actions

Guide

Guide to group actions This guide provides an introduction to the various methods of litigating on a multi-party basis, addressing the key legal issues to be considered throughout a claim.

Download report Begin

Introduction

The mass provision of goods and services, the proliferation of online delivery channels and the advance of big data make commercial mistakes on an industrial scale ever more likely. Damage to thousands or even millions of people means group actions are on the rise.

This guide provides an introduction to the various methods of litigating on a multi-party basis, addressing the key legal issues to be considered throughout a claim. From identifying the claim, choosing an appropriate procedural mechanism for the claim to be brought and exploring how claims can be funded and should be organised, through to addressing case management issues, questions relating to costs, and how to deal with settlement, this guide will equip you with everything you need to know about group actions. While this guide touches on all the different mechanisms and procedures available, it focuses on opt-in group actions relating to general commercial claims, rather than, for example, collective proceedings in the Competition Appeal Tribunal (CAT).

Our team of specialist litigators knows how to develop and pursue group litigation procedures of all types, including Group Litigation Orders (GLOs), representative actions, test cases, and competition damages litigation in the CAT. We have a particular reputation for winning claims connected with financial products, data issues and regulatory breaches. The size and breadth of our overall litigation practice, allied with the depth of our relationships with funders, brokers and After The Event (ATE) insurers means that we can negotiate and structure funding for even the most complex group action. Our connections with leading barrister chambers also give us access to the finest procedural minds; a huge benefit to those trying to develop and launch novel and complex claims. Our clients range from retail investors and SMEs, to high net worth individuals and institutions, all of whom for their own reasons appreciate the benefits of litigating as part of a group, often backed by litigation funding and ATE insurance.

Identifying claims

The first step in any group action is identifying a suitable claim. There is generally no limit on the subject matter of the claim, provided that a number of people have been affected in similar ways. Thus, past multi-party claims have included:

Securities actions brought pursuant to the Financial Services and Markets Act 2000;
Medical negligence claims arising out of the PIP breast implant scandal;
Claims for the misuse of personal data;
Environmental damage claims following an oil spill;
Claims under business-interruption insurance policies following the Covid-19 pandemic; and
Standalone or follow-on competition damages claims.

Multi-party litigation often, although not always, arises in circumstances where a party has been adversely affected by someone else's conduct, but where their loss is not large enough to make an individual claim economically viable. Group actions enable the costs of litigation to be spread between claimants (often with the benefit of specialist funding arrangements), enabling such actions to be brought. However, to take the benefit of these economies of scale, a sufficient number of claimants must be identified before proceedings are issued. This "bookbuilding" process can be challenging and time-consuming, and may necessitate the assistance of claims management companies who take an active role in seeking out prospective claimants.

It is vital at this stage to assess the merits of each individual case. Weaker claims can have a detrimental effect on the case as a whole and should be weeded out at the outset. Caution must also be exercised in relation to limitation issues and in ensuring that each claimant has given the requisite authority to act on their behalf.

Different procedural mechanisms

Determining the appropriate procedural mechanism for bringing multi-party proceedings is key. Broadly speaking, there are four mechanisms available under English law.

Group Litigation Orders

One of the main procedural tools for bringing multi-party proceedings in England and Wales is the Group Litigation Order (GLO) – an order which provides for the case management of separate claims which give rise to common or related issues of fact or law. There have been over 120 GLOs made since the regime was first introduced in 2000.

An application for a GLO may be made before or after the relevant claims have been issued. Although there is no prescribed minimum number of claimants, "far more than two … are necessary" (Austin & Ors v Miller Argent (South Wales) Ltd (2011)). If the court is satisfied that there are, or are likely to be, a number of claims giving rise to common or related issues (the GLO issues), then it may make an order. The court will also consider the overriding objective, which requires the court to deal with cases justly and at proportionate cost; the availability of other procedural mechanisms; funding; and the wider context of the claim. Thus, in Webster v Treloars Trust (2025), the court concluded that a GLO was inappropriate, particularly where a statutory compensation scheme had already been established.

Where a GLO is made, the managed claims will be entered onto a group register, which is usually established and maintained by lead claimant solicitors. Other claimants may "opt-in" to the GLO once their claim is issued, although the GLO will also typically specify a "cut-off" date, after which claimants can only be entered onto the group register with the court's permission.

Any judgment or order given in a claim on the group register in relation to one or more GLO issues will be binding on all the other parties on the group register at the time the judgment or order is given, unless the court orders otherwise. In AXA Sun Life Plc & Ors v HMRC (2024), the Court of Appeal made such an order, but emphasised that it did so on the basis of exceptional facts, and that in the ordinary course parties to claims on a group register should expect to be bound by decisions on GLO issues.

Representative actions

An alternative route for bringing proceedings on behalf of a group of claimants is the representative action procedure, under CPR 19.8. This longstanding rule, deriving from cases in the 16th and 17th centuries, provides that, where more than one person has the same interest in a claim, the claim may be brought (or defended) by a representative of the group.

In contrast to a GLO, in a representative action only the representative is a party to the proceedings. However, the represented parties will be bound by any determination. Although a court order is not required for an individual to become a representative under CPR 19.8, a defendant may apply to strike out the proceedings on the basis that the claim is not suitable for a representative action or may seek an order that a person may not act as a representative. Such applications often turn on whether the "same interest" test has been met (although even where it has been met, the court may exercise its discretion not to allow the claim to proceed in a representative capacity if it is not in accordance with the overriding objective).

In Lloyd v Google (2021), the Supreme Court considered that the purpose of requiring the representative to have the "same interest" in the claim as the persons represented was to ensure that the representative could be relied on to conduct the litigation in a way which would effectively promote and protect the interests of all members of the represented class. While this is not possible if there is a conflict of interest between class members, the existence of divergent interests will not preclude a representative action. Where individualised assessment of damages is required, the claimants will not have the "same interest" (Lloyd; Prismall v Google (2023), unless the damages can be assessed on a basis that is common to all members of the class (Lloyd; Commission Recovery Limited v Marks & Clerk LLP (2024)). However, in cases with both common and individual issues, the Supreme Court suggested the representative procedure could still be applied to the common issues (see "Trials" below).

There is no conflict just because some claimants have provided more information than others, nor because the defendant takes a defence of limitation against individual class members, nor because a substantive defence applies only to some members of the class (Commission Recovery Limited v Marks & Clerk LLP (2023)). Where there is no conflict, it is realistic for the represented group to place reliance on the representative claimant and its lawyers to pursue vigorously lines of argument not directly applicable to the claimant’s individual case (Commission Recovery (2023)).

Although representative actions are typically brought as opt-out proceedings on behalf of a defined group who are not individually identified, they can be brought on an opt-in basis (see, for example, Wirral Council v Reckitt and Indivior (2023)). Further, although, as the Supreme Court emphasised in Lloyd v Google, the ability to act as a representative does not depend on the consent of the persons represented, it is open to the judge managing the case to impose a requirement to notify members of the class of the proceedings or limit represented parties to persons who have positively opted in.

Since the comprehensive updated guidance on the use of representative actions provided in Lloyd v Google, there have been a handful of claims brought in this way (with very few judgments), and use of the procedure continues to develop. The Supreme Court in Lloyd noted that CPR 19.8 is "a flexible tool of convenience in the administration of justice". It is sufficient that there is one or some common issues that can be determined by a representative action, even if other issues can only be resolved on an individual basis (Lloyd; Commission Recovery (2024)). The mechanics of distributing any final damages among the class is a question that can be left until a later stage of proceedings (Commission Recovery (2023)).

So far, the courts appear to consider that claims for declaratory relief (rather than damages) are most suited to the representative procedure (see Commission Recovery (2024), a case which settled before trial), although that does not mean that all representative claims for declarations will be allowed to proceed (as was the case in Wirral Council v Reckitt and Indivior – see further below).

A further representative procedure is available under CPR 19.9 in relation to claims about estates, trust property or the interpretation of documents, where the court may appoint a representative on behalf of unborn children, or those who cannot be found or identified.

Multiple claimants on single claim form (or consolidation)

Alternatively, claimants may simply opt to bring all their claims together in a single action. In some cases, this power may be combined with an application for a GLO.

Under CPR 19.1, any number of claimants or defendants may be joined as parties to a claim and in Municipio de Mariana v BHP (2022), the Court of Appeal permitted a claim brought by over 200,000 claimants to continue, ultimately resulting in success for the calimants. CPR 7.3, meanwhile, provides that a single claim form can be used to start all claims which can be "conveniently disposed of in the same proceedings". Provided this test is met, there is no absolute limit on the number of claimants that can appear on a single claim form (Morris & Ors v Williams & Co Solicitors (2024)), although the number of claimants is a factor that may be relevant to whether the court will permit multiple claims to go forwards at the start in an omnibus claim form (Angel v Black Horse Limited (2025)). Other relevant factors include whether the claims involve the same causes of action, whether the case specific claims and defences do or are likely to raise common issues of law or fact, and whether decisions in lead or test cases will be significant for the disposal of following cases, either because they will bind the parties or be persuasive in the disposal of issues.

The English court also has broad case management powers, and so it is possible for existing claims to be consolidated, for claims to be case managed together, or for claims to be tried together but otherwise proceed separately. As noted in Adams v Ministry of Defence (2024), the court may also disaggregate claims brought on a single claim form where, for example, generic issues have been determined and each claim falls to be individually assessed.

Collective proceedings before the CAT (in competition actions)

In the context of competition law infringements, opt-in and opt-out collective actions may be brought before the Competition Appeal Tribunal (CAT) by a certified class representative pursuant to section 47B of the Competition Act 1998.

However, unlike representative actions under CPR 19.8, collective proceedings before the CAT may only be litigated if the CAT makes a collective proceedings order (CPO). It will only do so if the claim is brought on behalf of an identifiable class of persons, raises the same, similar or related issues of fact or law, and is suitable to be brought in collective proceedings. Further, although the representative does not need to be a class member, the Tribunal will only make a CPO if it considers it is just and reasonable for that person to act as a class representative.

Derivative actions

Arguably another form of group action is the derivative action, whereby a minority shareholder brings proceedings on behalf of a company against one or more of its directors for negligence, default, breach of duty or breach of trust. Derivative actions represent an exception to the principle that it is for the company to determine whether to pursue such a claim, and the court's permission is therefore required for the shareholder to continue the claim. As well as satisfying certain preconditions, including that the claim is not contrary to the duty to promote the success of the company, the shareholder must establish a prima facie case. For this reason, derivative claims have proved difficult to get off the ground.

Arbitration

Although arbitral rules are making increasing provision for joinder and consolidation of claims, the consensual nature of arbitration means that multi-party arbitrations can often be difficult to accommodate. Arbitration clauses rarely provide expressly for group arbitration, and where a party is resistant, a tribunal is unlikely to force them to arbitrate on a collective basis.

Nevertheless, group actions in English seated arbitration are not unknown, particularly in circumstances where multiple separate proceedings appear otherwise unavoidable, and the efficiencies of group proceedings are attractive to defendants as well as claimants. For example, in 2020 around 400 companies formed the Hiscox Action Group and commenced arbitral proceedings against their insurer, in relation to claims under business interruption policies for losses suffered during the COVID-19 pandemic. Defendants may also be attracted by the confidential nature of arbitration, the ability to choose specialist arbitrators and the flexibility of the process.

Funding claims

A significant contributor to the development of group actions in England and Wales has been the growth of the third-party funding market. In circumstances where claimants may struggle to finance proceedings, third-party funding provides an invaluable means of obtaining access to justice, provided the claim passes the applicable merits threshold. Funding can be particularly beneficial at the outset of proceedings, to enable the claim to be properly investigated and to facilitate an effective bookbuild. Funding agreements typically provide for the funder to cover the costs of proceedings in return for either a share of the damages, a multiple of the amount invested, or a combination of the two.

The third-party funding market was, however, dealt a blow by the Supreme Court's decision in R (on the application of PACCAR Inc & Ors) v Competition Appeal Tribunal & Ors (2023), where it was held that agreements which provide for funders to receive a return based on a percentage of the damages awarded constitute damages-based agreements (DBAs). DBAs are entirely prohibited in the context of opt-out collective proceedings in the CAT, and in other cases they must meet the requirements of separate regulations to be valid. As a result, PACCAR cast doubt on the enforceability of many existing funding agreements, leading to renegotiation of terms, and calls for statutory intervention. However, in decisions which were subsequently upheld by the Court of Appeal, the CAT concluded that agreements which provide for a return based on a multiple of the amount invested remain effective, and that it may be possible to sever offending provisions where an agreement provides for a combination of returns.

Initial legislative attempts to reverse the PACCAR decision were stalled by the 2024 general election. However, in December 2025, and following wide ranging recommendations on the reform of litigation funding by the Civil Justice Council (CJC), the Government confirmed its intention to introduce legislation accordingly "as soon as parliamentary time allows". Unfortunately, no mention was made of the proposed legislation in the 2026 King's Speech. The Government's response to the CJC's other recommendations, which included the introduction of "light-touch" statutory regulation of litigation funding, with additional requirements where funding is provided in collective proceedings, representative actions or group litigation, is awaited.

In the context of commercial actions, including multi-party proceedings, under current rules there is normally no obligation to disclose funding arrangements to the opponent unless the court orders otherwise (for example, where a third party costs order is sought). However, when determining whether or not to make a collective proceedings order, the CAT will consider whether a proposed class representative will be able to pay the defendant's costs if ordered to do so, and will therefore examine any funding agreement in place.

As well as securing third-party funding, claimant groups are also likely to seek the protection of insurance policies, such as "After the Event" policies, to protect against the risks of being ordered to pay defence costs. Again, there is no obligation to disclose the existence of an insurance policy to the opponent. However, in many cases claimants may choose to do so, particularly in response to an application for security for costs, in order to demonstrate that the claimant will be able to pay the defendant's costs if required to do so.

Organising

Where group actions are brought on behalf of claimants represented by different legal teams, careful thought must be given at the outset to the way that the claims are organised and run.

Competing legal teams can lead to duplication, confusion and misunderstandings and, while parties to litigation are generally entitled to be represented by solicitors of their choice, in group litigation the courts have acknowledged that right is qualified in order to achieve efficient conduct and case management.

In APK Communications & Ors v Vodafone Ltd (2026), the court emphasised that legally represented co-claimants bringing claims within one set of proceedings must be jointly represented, unless the court makes an order authorising separate representation. Such orders, which will be made to avoid injustice, are the exception rather than the norm.

In the context of GLOs, the rules provide that, as a preliminary step, it will often be convenient for the claimants' solicitors to form a group and for one of that group to take the lead in applying for the GLO and in litigating the GLO issues. The lead solicitor's role and relationship with other members of the group should be carefully defined in writing and, as noted above, they will go on to manage the group register. While such an arrangement is unlikely to be necessary in the context of a representative action, where the only claimant is the representative, it is usually sensible to adopt a similar process in multi-party proceedings under other procedural mechanisms, even if not strictly required.
In some cases, more than one lead solicitor has been appointed under a GLO. For example, in 2017 two lead solicitors were appointed in relation to a GLO over personal injury claims by former British Steel coke oven workers. This approach can be effective where roles and responsibilities can be effectively delineated, but there is a risk of satellite disputes and the court will typically exercise caution before appointing additional lead solicitors against the reasoned opposition of existing lead solicitors.

By contrast, in Lungowe v Vedanta Resources Plc & Ors (2020), the court made clear that, at least in relation to resolving GLO issues, different groups of claimants are not entitled to instruct different groups of counsel. The principle was, in the court's view, "so obvious that it does not appear to have been stated anywhere expressly before", and "no court should be faced with different counsel teams acting for the same cohort, save in the very rarest of circumstances which it is not possible fully to envisage."

Where there are numerous claimants, or the claimant group includes claimants of different categories (i.e. individuals, private legal entities, public legal entities, mixed corporations), it will also be helpful to ensure that clear decision-making structures are put in place at the outset, to avoid unnecessary delays if every member of the group has to be consulted on every step in the litigation process. In some cases, the claimants may choose to appoint a claimant / client steering committee, adopt a voting system or even, where justified by the number of claimants, form a limited company.

In especially complex cases with multiple defendants and/or defendants in multiple jurisdictions, there may also be a defence steering committee, which performs the same function for the defendants.

While the establishment of a steering committee does not require a court order, the court usually gives directions on who will be a member of the committee and how the committee will act within the litigation. For instance, the claimant firms may submit a list of which firms they believe should be in the committee. The court will then analyse the list and may propose amendments based on considerations such as a specific firm’s experience. As the court observed in the Pan NOx Litigation (2025), while the use of multiple lead firms and/or a steering committee will inevitably result in higher incurred costs than one well-resourced firm, it is incumbent on such firms to keep their interactions within reasonable bounds.

In addition to steering committees, the additional layer of complexity inherent in group actions often demands the engagement of a claims management company (CMC), also known as a claims administrator (although this latter designation has been more commonly utilised within the realm of settlement administration firms). CMCs specialise in efficiently handling the administrative tasks associated with aggregating a large group of clients (e.g. developing marketing campaigns and managing the growth of the class) and providing client care throughout the proceedings, processing and validating claims (e.g. collecting claim forms, verifying eligibility – including on-field operations for claims that relate to events that occurred in remote locations, and calculating individual claim amounts). Their participation helps streamline the claims process, reducing not only the administrative burden on the court and the costs to the parties but also the overall timely resolution of the case.

The use of a CMC also assists law firms with compliance requirements, as CMCs are usually familiar with legal requirements such as client care obligations and court-approved distribution plans governing the administration of settlements. CMCs can also provide documentation to demonstrate that the firms involved in the case are acting in accordance with court orders. Overall, CMCs play a critical role in ensuring the proper conduct of group actions, and having them involved from the outset of any given case is advisable to enhance efficiency, accuracy, and compliance, ultimately benefiting all parties.

Limitation

Limitation may be a complex issue when litigating group actions, not only because the claimant firms need to handle different limitation dates for many different claimants, but also because the same claimant may have multiple claims subject to differing limitation dates. There are various ways of dealing with this issue:

Establish subclasses: depending on how many different categories of claimants and/or limitation periods apply, it is possible for the court, at its own initiative or at the request of one or more of the parties, to establish subclasses or groups, each with separate representation, ensuring that limitation issues can be addressed separately from the rest of the class.
Standstill agreements: these are agreements between the claimants and defendants that suspend the running of time for limitation purposes for one or more of the claims being litigated. They are commonly entered into during settlement discussions.
Class certification: in most cases a GLO will include a cut-off date, by which claimants will need to register, although in some cases the expiry of the limitation period may act as an effective cut-off.

Jurisdiction

In order for a group action to be heard by the English courts it will be necessary to establish jurisdiction. In some cases, the jurisdiction of the English court will be clear. However, where claims concern events that occurred abroad or defendants are domiciled elsewhere, then jurisdiction arguments may well arise.

Under the common law, jurisdiction is based on service of proceedings and so, if the defendant is domiciled in England or can otherwise be served here, commencing proceedings will be relatively straightforward. However, a defendant may still seek to challenge the English court's jurisdiction on the basis that there is a more appropriate forum to hear the claim. As Limbu v Dyson Technology Limited & Ors (2024) shows, in determining the appropriate forum, the court may take into consideration such matters as the ability to obtain funding for the claims and equality of arms.

Where a defendant is located outside the jurisdiction, it will generally be necessary to obtain the court's permission to serve proceedings on them, unless there is an applicable jurisdiction clause in favour of the English courts. When seeking permission, the claimant must show a serious issue to be tried on the merits, a good arguable case that the claim falls within a relevant "gateway", and that England is clearly or distinctly the appropriate forum to hear the claim. The gateways are many and varied, but include claims in tort where damage has been sustained in the jurisdiction, a breach of contract committed within the jurisdiction, or claims for misuse of private information where detriment has been suffered within the jurisdiction. Where claimants seek to bring proceedings against both an English company and its foreign subsidiary, as is often the case in the context of mass tort claims, they may also avail themselves of the "necessary or proper party" gateway (Vedanta Resources PLC and another v Lungowe and others (2019)). In certain circumstances claimants may be able to show that the parent company owes a duty of care for the activities of its foreign subsidiaries (AAA v Unilever PLC (2018)), for instance as a result of the level of control the parent company exercises over the subsidiary's operations (Okpabi v Royal Dutch Shell (2021)).

The law applicable to the dispute will depend on the nature of the claim. In contractual claims, the governing law will normally have already been specified in the underlying agreement. The position in tort claims is less straightforward. The applicable law will generally be the law of the country where the damage occurs, but specific rules may apply in some circumstances, including in relation to product liability claims. Complex issues can, however, arise in multi-party proceedings where different governing laws apply to different claims. The English courts can, of course, determine cases on the basis of foreign law, which is a matter of fact, proven by expert evidence. As noted in Alame & Ors v Shell Plc & Ors (2025), in such circumstances the task of the court is to evaluate the evidence and predict the likely decision in the highest court in the foreign jurisdiction as if the case had been litigated there. The existence of different governing laws may lead the court to determine that claims lack the "same interest" required for a representative action.

Issue

Once the claimant group is ready to issue proceedings, thought must be given to where they should do so. Other than in relation to claims under a CPO, which must be dealt with by the CAT, there is no assigned court for multi-party proceedings.

Instead, it will be necessary to consider the subject matter of the claim, its value and complexity. For this reason, while multi-party proceedings may be commenced in the County Court, it is more likely that it will be more appropriate to issue proceedings in the High Court.

As noted above, a GLO governs multiple claims, while a representative action is a single claim brought on behalf multiple parties. An application for a GLO can be made before or after the claims are issued. While it is not necessary to identify all the potential claimants that will be joined once the GLO is made, the courts have emphasised that a GLO should not be used to establish a claimant group, and so an applicant will need to provide supporting evidence to demonstrate that the requisite number of claimants intend to join.

An order for a GLO requires, in the King's Bench Division, the consent of the President of the King's Bench Division; in the Chancery Division, the consent of the Chancellor of the High Court; and, in the County Court, the consent of the Head of Civil Justice.

Test claimants

In group litigation it may be effective for the court to direct some claims to proceed as test or lead to claims, whilst staying the remaining claims, resulting in considerable time and cost savings.

As noted by the Court of Appeal in Alame v Shell (2024), "one of the advantages of the process of selecting lead cases is to concentrate the minds of the parties on the real issues in dispute and how to cover a wide spread of those issues using a proportionate number of lead cases as the vehicles for addressing them." Any decision made in respect of a test case will generally be binding on the remaining claims, at least in respect of the common issues in the action.

In some cases, claims may be selected on a random basis, but the court may alternatively order the parties to select test cases between them. Careful consideration will need to be given to identifying appropriate test claims for this purpose. For obvious reasons, the claimants will wish to present their strongest case, while the defendants will want the court to consider the weakest, but including too many cases will inevitably reduce the efficiencies of ordering test claims in the first place. The court will also be concerned to ensure that the test cases cover a range of fact patterns and that all of the common issues in the action are addressed, even if not every test case covers every issue.

Case management

By nature, the large number of parties in a group claim can result in more complex (and more expensive) case management issues.

The English courts have wide ranging and flexible case management powers, which are readily wielded in the context of group actions in an effort to narrow the issues and try them effectively. The CPR requires the court to further the overriding objective by actively managing cases, including by deciding the order in which issues are to be resolved and fixing timetables or otherwise controlling the progress of the case (CPR 1.4). As well as ordering a trial of test claims, the court may order a preliminary issues trial or a split trial, or alternatively, in representative proceedings, may bifurcate claims to determine common issues first and then deal with individual issues (for instance, relating to liability or quantum) in separate group or individual claims. If there is a split trial, there may also be a question of to what extent progress should be made on issues that have been deferred to the later trial while the first trial is ongoing (such as disclosure or the preparation of witness evidence).

In the context of a GLO, a managing judge will be appointed to oversee the claims. They are likely to give various directions when the GLO is made, including specifying the approach that should be taken to statements of case. The claimants may be required to serve group particulars of claim, together with separate individual particulars, or alternatively specific facts about each claim may be obtained through questionnaires or a schedule appended to the group particulars. The extent to which the defendant is obliged to deal with each individual claim will vary, although the defendant will certainly need to serve a defence in response to allegations in the group particulars. In other group actions that are not GLOs, the judge (or judges) assigned to hear case management conferences will have regard to many of the same considerations.

For instance, in securities group actions brought pursuant to the Financial Services and Markets Act 2000, there is a developing line of cases identifying a split of issues to be dealt with at a first trial followed by a second trial, with sample claimants fully involved throughout and the remainder of the claimants providing more limited information. An attempt in Wirral Council v Reckitt and Indivior to seek declaratory relief in respect of common liability issues as a representative action, with individual claims for damages to follow, was struck out by the court on the basis that such a bifurcation would oust the jurisdiction of the court to case manage the claims from the start (a decision upheld on appeal).

Effective case management will be particularly important when it comes to controlling the costs of disclosure. The disclosure process is vital in group actions, particularly in circumstances where many of the relevant documents lie in the hands of the defendant. However, in circumstances where even the most straightforward dispute can involve a vast disclosure exercise, the complexities of multi-party claims can create particular challenges. Notably, while group actions in the Business and Property Courts will be subject to the rules on disclosure set out in PD 57AD, it is expressly acknowledged that in multi-party cases it may be appropriate vary the disclosure timetable and procedure to meet the needs of the case. Disclosure may, however, be more straightforward in circumstances where the court has ordered a trial of test claims, enabling the disclosure exercise to be limited to those cases. Similarly, if the court can be persuaded to order a preliminary issues trial, the court may be prepared to limit disclosure to the issues in the first trial (Alame & Ors v Shell Plc & Anr (2024)).

Issues can also arise in group litigation in relation to who has access to disclosed documents. In this respect, PD 57AD encourages the parties to discuss and seek to agree whether it is appropriate for all of the disclosing party's documents to be given to all the other parties, or only to some via, for example, a confidentiality club.

Trials

As noted previously, in multi-party litigation it will often be impractical for the court to deal with the entirety of the claims in a single trial. Accordingly, the court may order a trial of preliminary issues, a split trial or a trial of test cases. However, parties should be aware that multiple trials do have the potential to lead to delay, higher costs and repetition.

In representative proceedings, it has been suggested that the court may also order bifurcation, whereby common issues of law or fact are dealt with by way of a claim for a declaration, with issues of liability or quantum dealt with separately by way of individual proceedings, or on an alternative group basis. However, although the Supreme Court appeared to approve of this approach in Lloyd v Google, in Wirral Council v Reckitt and Indivior (2023) the Commercial Court refused to permit a securities claim to proceed by way of a bifurcated process, concluding that allowing the representative action to proceed would be unfair, unjust and contrary to the overriding objective. The Court of Appeal agreed with the Commercial Court's decision, emphasising the importance of the court's ability to exercise its case management powers over all members of the claimant group (Wirral Council v Reckitt and Indivior (2025)).

Settlement and payment

As in litigation more generally, throughout multi-party proceedings the court will encourage the parties to seek to settle their dispute and the significant costs that may be incurred in group actions provide greater impetus on both sides.

However, managing the interests and wishes of a diverse group of claimants can sometimes be challenging when dealing with settlement negotiations, particularly in circumstances where clear thought has not been given at the outset to appropriate decision-making procedures. Where the claim is supported by litigation funding, it is also likely to be necessary to take account of funders' views, although under English law funders are not generally permitted to disproportionately control the litigation.

In some multi-party proceedings, including claims under GLOs, it may be possible for some of the claims to settle while others continue to run, although claimants should be aware that if stronger claims are settled, this may have a detrimental effect on the remaining proceedings. Meanwhile, in order to bring the proceedings to a close, a defendant is likely to prefer a universal settlement.

In the context of a GLO or a representative action under CPR 19.8 it is not necessary for the court to approve terms of settlement unless the claimants include children or protected parties, although approval is required for a representative action under CPR 19.9. In the CAT, settlements of opt-out collective actions require approval by the Competition Appeal Tribunal, which is required to assess whether the terms are just and reasonable. In Merricks v Mastercard & Ors (2025), the CAT observed that the focus of this test is on the class members.

The mechanics regarding the payment of settlement sums will also be a question of agreement between the parties. In practice, sums are often paid to the claimants' solicitors, who will then be responsible for distribution amongst the claimant group.

Judgments and enforcement

A judgment will generally only be binding on the parties to it, who will be precluded from challenging it in separate future proceedings under the doctrine of res judicata.

However, where a judgment is given in relation to a claim on the group register in relation to one or more of the GLO issues (for example, in respect of a test case), it will be binding on the parties to the other claims on the register at the time the judgment is given, unless the court orders otherwise. Similarly, a judgment made in representative proceedings will be binding on all those represented in the claim, although it may only be enforced by or against a person who is not a party to the claim with the court's permission.

Under the common law the English courts will generally recognise and enforce foreign judgments for a debt or definite sum of money, where the judgment is final and conclusive and the original court had jurisdiction. Various other enforcement regimes may also apply. It is therefore likely that, provided any foreign judgment in a class action meets these criteria, it will also be recognised and enforced. However, the question of whether such a foreign decision will have preclusive effect, and thus prevent class members from attempting to relitigate issues before the English courts, is unclear, particularly in respect of class members that did not take an active role in the foreign litigation but nevertheless did not specifically opt out.

Costs issues

The complexity of multi-party proceedings means that the costs incurred by each of the parties can be significant. One of the tools available to the court to control litigation costs is costs budgeting. In many cases, the value of a group action is likely to exceed the £10 million threshold for the application of the English court's automatic costs budgeting regime. However, costs budgeting will also apply where the claim form does not state that the claims are valued in excess of £10 million, and the court retains a general discretion to order costs management at any time. Costs management orders have thus been made in respect of a number of group actions, including White & Ors v Uber London Ltd & Ors (2025), where the court noted that costs budgeting would give the claimants visibility of their exposure in respect of the defendant's costs at an early stage of the case in circumstances where a preliminary issue trial had been ordered.

Equally, one of the key benefits of a group action is the efficiency that comes from determining common issues in a single set of proceedings. However, inevitably not all the work on a case will relate to every claim, and so multi-party proceedings can also involve complex questions around costs allocation.

In the context of a GLO, specific rules govern costs recovery, distinguishing between individual costs (costs incurred in relation to an individual claim on the group register) and common costs (costs incurred in relation to the GLO issues, individual costs incurred in a claim while it is proceeding as a test claim, and costs incurred by the lead legal representative in administering the group). In the Pan NOx Litigation (2025), the court noted that common costs claimed by non-lead firms "should be extremely limited", since their core work of looking after clients should be claimed in individual costs. Although there have been some suggestions that hourly rates in respect of common costs work might be higher than rates for individual cases, that suggestion was rejected in Hutson (Deceased) & Ors v Tata Steel UK Ltd (2025). The general rule is that all the members of the group will have several liability for an equal proportion of the common costs, together with individual liability for costs on their own claim. Where common costs have been incurred before a claim is entered on the group register, the court may order that claimant to be liable for a proportion of those costs.

By contrast, in a representative action, generally speaking only the representative will be liable for costs (although in practice any costs liability is likely to be covered by third-party funders and ATE insurance). It is, in theory, possible for the court to make a third-party costs order against a represented party but such orders are unusual.

Where multiple claims are brought together, the general position is that each party is liable jointly with each other for the whole of the reasonable costs of their common claim or defence, but only severally for the individual costs of their claim (see, for example, Baroness Lawrence of Clarendon OBE & Ors v Associated Newspapers Limited (2025)). However, in Re Ingenious Litigation (2020), which concerned claims by investors in various film finance partnerships, the court suggested that liability for adverse costs should be apportioned on the basis of their cash investment, such that the claimants shared risks proportionately to the possible rewards.

Key contacts

Key Contacts

To find out more about our Group Actions team, visit our Group Litigation page.