If you buy professional indemnity insurance for a solicitors' practice, surveyors' firm, accountancy or any other regulated professional services business, AIG Europe Ltd v Woodman is the most important aggregation case of the last decade. Aggregation is the unglamorous bit of your PI policy that decides whether ten related claims share one limit of indemnity or eat ten separate limits. Get it wrong and a £2 million policy can suddenly look like a £200,000 policy across ten matters.
The Supreme Court's 2017 ruling is the leading authority on what the words "one or a series of related matters or transactions" actually mean — words you will find, in identical or near-identical form, in the SRA Minimum Terms and Conditions and in most professional indemnity wordings sold in the UK market. This piece explains the case, the principle it lays down, and what we recommend buyers do at proposal, notification and claim stages as a result.
At a glance
- Court: Supreme Court of the United Kingdom
- Judgment date: 22 March 2017
- Neutral citation: [2017] UKSC 18
- Sector affected: Solicitors most directly, but the reasoning travels to every professional whose policy contains a "series of related matters or transactions" aggregation clause (surveyors, accountants, financial advisers, IT consultants, design and construction professionals).
- Practical impact: The Supreme Court re-set the test for aggregation. Claims aggregate where the underlying matters or transactions are connected in a "real" rather than fanciful way, and the connection has to be one that, looking at things objectively and in the round, "fits" with the aggregation language.
The facts
The litigation arose out of two failed property investment schemes promoted between 2005 and 2008. The Midas International Property Development Plc schemes pooled investors' money to develop holiday resorts — one in Turkey, one in Morocco. The schemes were marketed to UK investors who paid their money into client accounts held by the International Law Partnership LLP ("ILP"), a firm of solicitors. ILP was supposed to release the money only when the development sites had been secured with adequate "trust protection" — broadly, security taken over the land so investors' money was protected if the developments failed.
Both schemes collapsed. Around 214 investors lost approximately £10 million between them. The investors sued ILP, alleging that the firm had released their money in breach of trust because the security taken over the underlying land was inadequate or non-existent. ILP went into administration. The investors then pursued ILP's professional indemnity insurer, AIG Europe Ltd, under the third-party rights legislation and the SRA Minimum Terms.
ILP's policy had a £3 million limit of indemnity "for each claim". An "Aggregate Limit of Indemnity" applied to "all Claims arising from… one act or omission… one series of related acts or omissions… the same act or omission in a series of related matters or transactions… [or] similar acts or omissions in a series of related matters or transactions." AIG argued that all 214 claims arose from "similar acts or omissions in a series of related matters or transactions", that they all aggregated, and that its total exposure was therefore capped at the £3 million single-claim limit. The investors said the claims could only be grouped by scheme (the Turkey scheme and the Morocco scheme were entirely separate developments), or perhaps not aggregated at all, in which case AIG faced up to 214 separate £3 million exposures.
At first instance, Teare J ([2016] EWHC 2615 (Comm)) sided largely with AIG, finding that the matters were sufficiently related. The Court of Appeal disagreed and adopted a narrow test requiring "an intrinsic relationship between transactions, not an extrinsic relationship through a third common factor". On AIG's appeal, the Supreme Court was asked to decide which approach was right.
The legal issue
The question for the Supreme Court was how the phrase "a series of related matters or transactions" — drawn verbatim from clause 2.5(a)(iv) of the SRA Minimum Terms and Conditions — should be construed. The clause is functionally identical to language found in many professional indemnity wordings, so the answer mattered well beyond the immediate dispute.
The Insurance Act 2015 does not legislate the aggregation clause directly. But aggregation interacts with three live areas the Act does govern. First, the duty of fair presentation under Insurance Act 2015 section 3 ("s.3") requires the buyer to disclose every material circumstance the buyer knows or ought to know, including circumstances that might give rise to a series of related claims. Second, section 7 ("s.7") tells us when a circumstance is material — broadly, when it would influence the judgement of a prudent insurer. Third, section 14 ("s.14") abolished the common-law rule that the insured had a duty not to make fraudulent claims and replaced it with a statutory regime that turns on the insured's actions, not the insurer's perception.
AIG's argument was straightforward. The Turkey and Morocco schemes were administered by the same firm, used near-identical scheme documents, suffered from the same alleged flaw (inadequate trust protection), and produced claims with a common legal foundation (breach of trust through release of client money). That was a "series of related matters or transactions" — and "similar acts or omissions" had been committed across them. One aggregate limit should apply.
The investors argued for a "unifying factor" test. Aggregation should require something more than thematic similarity; it should require an intrinsic link between the transactions themselves, not merely a common breach by a common adviser. Without that limit, they said, every claim against a solicitor that arose from a particular type of work — wills, conveyancing, scheme work — would aggregate, which could not be what the SRA and the market intended.
The decision
The Supreme Court unanimously allowed AIG's appeal in part. Lord Toulson gave the leading judgment. The key passage is at paragraph 22:
"The words 'in a series of related matters or transactions' require an examination of the matters or transactions to see whether they are connected in some real way. There must be some 'inter-connection' between them, and that inter-connection must be one which, viewing matters realistically and in the round, would lead an objective observer to say that the matters are 'related' for the purposes of the clause."
The Court rejected the Court of Appeal's restrictive "intrinsic relationship" test. It also rejected any approach that required the transactions to be "dependent on each other" or "conditional upon each other". The test is open-textured and fact-sensitive: are these matters or transactions connected in a real way, taking a realistic view in the round?
Applied to the facts, the Court held that the Turkey and Morocco schemes were separate. Each scheme had its own development site, its own escrow arrangement, its own investor pool, its own trust deed. The fact that ILP made similar alleged errors across the two schemes did not, by itself, make the schemes themselves related. Within each scheme, however, the investors' claims aggregated — they were all participating in a single development project, in a common trust structure, with a common security failure.
The case was remitted for the aggregation question to be applied to the facts on that basis. The practical effect was that the 214 claims aggregated into two clusters, not one and not 214.
The principle established
In plain English, AIG v Woodman lays down three principles that anyone buying PI insurance in the UK needs to understand.
First, aggregation is fact-sensitive and contextual. There is no formula. Whether matters are "related" depends on how an objective observer, looking at the real-world facts in the round, would describe them. Your broker cannot tell you with mathematical certainty how a regulator or court will aggregate a future cluster of claims.
Second, common cause is not enough. The fact that a solicitor made the same mistake on twenty different files does not, of itself, make those files a "series of related matters". The matters themselves must be connected — through a shared transaction, project, scheme, fund, document set or counterparty — not merely through a shared adviser or a shared species of error.
Third, the test is the same across the SRA Minimum Terms and across most professional indemnity wordings using the "series of related matters or transactions" formulation. But the answer depends on the structure of the work the firm does. A solicitor specialising in single-project scheme work will aggregate very differently from one running thousands of independent conveyancing files.
What this changes for solicitors and PI buyers in 2026
Aggregation now sits at the centre of the renewal conversation. If you are buying PI insurance for a regulated professional firm, the practical implications are these.
At proposal stage, identify your "aggregation exposure clusters". Map your work into matters or projects that could be linked by an objective observer — schemes, funds, group conveyancing transactions, repeat instruction patterns, shared documentation. Disclose these clusters in your fair presentation under s.3. Insurers can and do use Woodman to argue that one shared limit applies across a cluster they were never told about. If you have told them, and they have rated for it, you are in a much stronger position.
At notification stage, notify by cluster, not by file. If a complaint comes in on one transaction within a connected scheme, the right notification is "a circumstance affecting [the scheme]", not "a circumstance affecting [the file]". This protects against under-notification and against the insurer later arguing that you failed to notify the wider problem. It also crystallises the aggregation point at notification rather than at claim.
At claim stage, anticipate the insurer's aggregation argument. Insurers tend to argue aggregation up when it caps their exposure and aggregation down when it triggers more deductibles. Your reasoning at notification should already address this — for instance by identifying the precise matters or transactions affected, the scheme structure, and the common security or document failure if any.
How insurers will use this case against you if you are not careful. Expect two moves. First, an insurer faced with a large cluster of claims will argue Woodman aggregation aggressively to bring everything inside a single limit. Second, an insurer faced with a fair-presentation challenge may say that you failed to disclose the scheme-level features that would have driven up the aggregate exposure — and treat that as a breach of s.3 with proportionate remedy under Schedule 1.
Five specific action points for the 2026 renewal:
- Schedule your scheme work. List every scheme, fund, syndicate or pooled transaction you are involved in. Attach the trust or scheme documents to the proposal.
- Map your repeat counterparties. If you have done twenty conveyances for the same developer or lender, that is a cluster.
- Stress-test your limit of indemnity. A £2 million limit applied across a 50-investor scheme is £40,000 per investor. Is that adequate?
- Notify by cluster, not by file. Train fee earners on what aggregation means in practice.
- Document your security and trust structures. Woodman turned on what the trust structure looked like. Insurers will ask the same questions.
How Apex applies this in practice
We treat aggregation as a renewal workstream in its own right. Before each renewal we sit with the firm and map its work into the buckets a court or arbitrator would recognise as "matters or transactions". For scheme-based practices we attach scheme documentation to the proposal. At notification, our claims team frames the notification by cluster where the facts justify it, with reasoned evidence on the file. Where a firm's work pattern creates concentrated aggregation exposure — typical for property scheme, fund and group conveyancing work — we model the limit through a Woodman lens, not a single-file lens. That is the difference between a policy that protects you and a policy that protects the insurer.
Related cases
- Spire Healthcare v Royal & Sun Alliance — the Court of Appeal applies and extends the Woodman test in a medical context.
- Bridgehouse Marketing v Wachsmann — fair presentation duty under s.3.
- Mutual Energy v Starr Underwriting — defects in fair presentation.
- Young v Royal & Sun Alliance — what counts as a "reasonable search" under s.3.
- MS Amlin v King Trader / Solomon Trader — claims handling duty under s.13A.
FAQs
Does Woodman still apply if my policy is not on SRA Minimum Terms? Yes, the principle applies to any policy that uses the phrase "series of related matters or transactions" or substantially similar wording. The Supreme Court's interpretation is taken as the modern English starting point for that phrase.
If I have two separate claims arising from the same conveyancing error template, do they aggregate? Probably not on their own. The matters themselves have to be connected, not just the error. Two unrelated buyers with no scheme link between them will usually not aggregate, even if the firm made the same mistake on both files.
Can I argue against aggregation if my insurer says claims aggregate? Yes. Woodman is a two-edged sword. Where aggregation helps you (one excess instead of many) you may want to argue for it; where it harms you (one limit shared across many claims) you may want to argue against it. The wording, the facts and the documentary trail will decide.
What if my work is mainly volume conveyancing or wills? Aggregation risk is generally lower, because each transaction is between different parties and has no scheme connection. But repeat work for a common lender, developer or fund may still cluster.
Does the duty of fair presentation under s.3 require me to disclose my aggregation exposure? You must disclose every material circumstance you know or ought to know. The structure of your scheme work, your concentration on particular counterparties, and any known cluster of complaints are material. The aggregation analysis itself is a circumstance: an insurer who is told you have a 200-investor scheme on the books will price differently from one who is not.
Will my insurer apply aggregation more aggressively after Woodman? Yes, on large clusters. Insurers know the case and use it. Brokers who do not raise aggregation at renewal are letting their clients walk into the insurer's strongest argument.
Is there a way to negotiate the aggregation wording? Sometimes. Outside SRA-regulated practice you have more flexibility on wording. We can negotiate "each and every claim" limits, scheme-specific reinstatements, or higher aggregate cover. Inside the SRA regime the Minimum Terms govern but excess layers can sit on different terms.
Sources
- AIG Europe Ltd v Woodman & Others [2017] UKSC 18 — full judgment on Bailii at https://www.bailii.org/uk/cases/UKSC/2017/18.html
- AIG Europe Ltd v OC320301 LLP (formerly The International Law Partnership LLP) and others [2015] EWCA Civ 1028 — Court of Appeal judgment.
- AIG Europe Ltd v The International Law Partnership LLP and others [2016] EWHC 2615 (Comm) — first-instance judgment of Teare J.
- SRA Minimum Terms and Conditions of professional indemnity insurance — current version on the SRA website.
- Insurance Act 2015 — full text on legislation.gov.uk, in particular sections 3, 7 and 14.
- Lloyd's Law Reports Insurance & Reinsurance, case commentary 2017.
Legal commentary, not legal advice. The application of these principles to any specific situation requires specialist advice. Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority, FRN 724952.