If you sit in a board meeting and hear the words "aggregation" and "series of related matters", Spire Healthcare v Royal & Sun Alliance is the case the brokers and lawyers in the room are thinking about. It is the leading post-AIG v Woodman authority on the "originating cause" form of aggregation language, applied in a clinical negligence context, and it is the most powerful illustration in the modern law of how a single rogue practitioner can collapse hundreds of separate claims into one event for insurance purposes.
For professional indemnity buyers in any sector where one individual professional can affect a large number of clients — solicitors, financial advisers, dentists, consultants, GPs, surveyors, accountants, IT contractors — the Spire reasoning matters even though the policy on the facts was a commercial property and liability policy. The Court of Appeal's analysis tells you how to read aggregation language, how to apply it to clusters of similar but distinct claims, and how to defend a "single originating cause" argument either way.
At a glance
- Court: Court of Appeal (Civil Division)
- Judgment date: 28 February 2018
- Neutral citation: [2018] EWCA Civ 317
- Sector affected: Healthcare directly; the reasoning travels to every professional sector with a rogue-practitioner exposure (financial advice, conveyancing, audit, clinical work).
- Practical impact: Confirmed the Woodman approach to "series" aggregation and provided a worked example of how an "originating cause" trigger can sweep hundreds of patient claims into one £20 million layer.
The facts
Spire Healthcare operated a number of private hospitals at which Mr Ian Paterson, a consultant breast surgeon, treated patients between 1998 and 2011. Paterson was eventually convicted of multiple counts of wounding with intent. Between his criminal trial and the civil litigation, hundreds of his former patients sued Spire on the basis that he had carried out unnecessary and inappropriate operations — partial mastectomies and other procedures that should never have been performed, or had been performed in a manner that left tissue behind and required re-operation.
Spire had liability insurance with RSA. The insurance was structured in layers. The relevant layer had a £10 million limit for "any one event" with an aggregate of £20 million across the policy year. The key wording defined an event as including "all individual losses arising out of and directly occasioned by one source or original cause" — language familiar to the market and importantly different from the "series of related matters or transactions" wording in Woodman.
When the Paterson claims started to roll in, Spire settled with the patient claimants and looked to RSA for indemnity. RSA argued that all of the patient claims aggregated as a single event because they were all "directly occasioned by one source or original cause" — namely Paterson himself, or his clinical conduct, or Spire's failure to supervise him. Spire's case was the opposite: each patient was a separate event because each had received a separate diagnosis, a separate consent process and a separate operation. The difference between the two positions in money terms was the difference between one £10 million limit and (potentially) many.
At first instance, HHJ Waksman QC (as he then was) held in RSA's favour. Spire appealed. The Court of Appeal had to decide whether the trial judge had correctly applied the "originating cause" test, and in particular how to reconcile that test with the Supreme Court's recent reasoning in Woodman.
The legal issue
The wording at the centre of the case used an "originating cause" trigger — not the "series of related matters or transactions" trigger considered in Woodman. That distinction is critical. "Originating cause" language is generally regarded as one of the broadest forms of aggregation language in the market. It looks for a single upstream cause from which the downstream losses flow.
Even so, the Woodman methodology — "look at the facts realistically and in the round, ask whether an objective observer would say the matters are connected" — supplied the analytical frame. Insurance Act 2015 section 3 ("s.3") and section 7 ("s.7") sat in the background: the fair presentation duty in s.3 expects buyers to disclose every material circumstance, and s.7 defines material circumstance as anything that would influence the judgement of a prudent insurer. A known supervisory gap around a single named practitioner is paradigmatically material.
Spire argued that the cause of each patient's loss was individual. Each patient consented to her own operation. Each consultation was independent. Each clinical decision was case-specific. The "originating cause" was the consultation between Paterson and the individual patient, not Paterson as a person.
RSA argued the opposite. The "originating cause" was Paterson's pattern of unjustified or improperly performed surgery, sustained over years and across hospitals. The losses were "directly occasioned" by his clinical conduct — and, at a higher level of generality, by Spire's failure to supervise him. Either characterisation produced one event.
The decision
The Court of Appeal (Simon LJ giving the leading judgment) dismissed Spire's appeal. The key reasoning is at paragraphs 30 to 32 of the judgment, where Simon LJ adopted the trial judge's analysis:
"[The trial judge] was right to find that the negligent performance of operations or wrongful advice to undertake operations by Mr Paterson on patients of Spire was a single 'source or original cause' for the purpose of the policy. The unifying factor is the conduct of Mr Paterson."
The Court accepted that "originating cause" is broader than "series of related matters". It expressly approved the trial judge's view that the question was a factual one — and that, on the facts, the single unifying factor was Paterson's conduct. The patients' individual consent processes, individual diagnoses, and the temporal spread of the operations did not break the chain.
The Court was careful to distinguish Woodman. In Woodman the wording was narrower; here it was broader. Woodman did not bar a finding that a single practitioner's pattern of conduct could be an originating cause. The two cases dovetail rather than contradict.
The practical consequence was that all of the Paterson patient claims aggregated as a single event. RSA's exposure on the relevant layer was one £10 million limit, not many. Spire absorbed the rest.
The principle established
Spire lays down three principles for the modern law of aggregation.
First, the aggregation language used in the policy matters more than almost anything else. "Originating cause" wording aggregates broadly. "Series of related matters or transactions" wording aggregates narrowly (after Woodman). "Each and every claim" wording does not aggregate at all. Buyers and brokers who ignore the precise language do so at the policyholder's peril.
Second, a single rogue or repeating actor can be an originating cause. Where one individual professional — surgeon, solicitor, IFA, surveyor, partner — repeats the same misconduct or error across many clients, an "originating cause" trigger will almost always treat that as one event. The pattern of conduct is itself the cause.
Third, Woodman and Spire together set the framework. Both require a realistic, in-the-round assessment. Both reject formalistic tests. Both place the decision on the wording first and the facts second.
What this changes for PI buyers in 2026
The Paterson litigation reshaped how every broker in the UK thinks about aggregation. For 2026 renewal, the practical implications for any firm with people who can affect many clients are:
At proposal stage, identify your key-person risk. If your firm or business has any individual — practitioner, partner, fee earner, adviser, consultant — whose conduct could affect a large number of clients, that is material under s.3. Disclose it. Quantify it. Show the controls. Insurers will want to know about supervisory structures, peer review, file audit, complaints history and continuing professional development for that individual.
At notification stage, if a pattern emerges across a particular individual's work, notify by individual, not by file. A "circumstance" under modern professional indemnity wordings is broad. Telling the insurer "we have identified a possible pattern with [name]" notifies all downstream claims from that pattern within the limit. Doing the opposite — notifying claim by claim — gives the insurer arguments later about late notification of the wider problem.
At claim stage, expect the insurer to deploy Spire aggregation if it helps them and individualise the claims if it does not. The argument runs in both directions. Your job is to make sure the contemporaneous documents support the characterisation that helps the policyholder under the precise wording in front of you.
How insurers will use this case against you if you are not careful. Two ways. First, on broad "originating cause" wordings, insurers will collapse multi-claim clusters into one limit using Spire. Second, on fair presentation challenges under s.3, insurers will argue that you withheld information about a known rogue or repeating actor — because, after Spire, the materiality of that information cannot really be argued.
Five specific action points for the 2026 renewal:
- Read your aggregation wording word for word. Identify whether it is "series of related matters", "originating cause", "any one event" or "each and every claim".
- Map your key-person risk. List every individual whose conduct could create a Spire-style cluster, with the controls around each.
- Stress-test your aggregate limit. If 100 of your clients sued the same fee-earner and aggregated, would your policy pay out?
- Adopt cluster notification. Train your complaints team to notify by individual or theme as well as by file.
- Review your supervision policy. Spire-type exposures are usually traceable to supervisory weakness. Insurers want to see the supervisory structure documented.
How Apex applies this in practice
We map aggregation language onto firm structure before every renewal. Where a firm has key-person concentration — common in legal, financial advice, medical and consultancy practice — we flag the Spire aggregation risk explicitly. We help draft the supervisory disclosures that go onto the proposal under s.3 and we structure notification practice so that pattern-based exposures are notified by pattern, not by file. Where insurers attempt aggregation to deprive a client of cover we have argued the Spire wording the other way successfully. The case cuts both ways; deploying it requires reading the wording properly and getting in front of the facts early.
Related cases
- AIG Europe v Woodman — the Supreme Court's foundational aggregation decision.
- Bridgehouse Marketing v Wachsmann — fair presentation under s.3 in a PI context.
- Mutual Energy v Starr Underwriting — fair presentation defects.
- Young v Royal & Sun Alliance — reasonable search under s.3.
- Ted Baker v AXA — conditions and proximate cause.
FAQs
Is Spire a PI case strictly speaking? Not on the facts — the policy was a public and products liability policy held by a hospital group. But the aggregation reasoning is general. It applies to PI wordings using "originating cause" or "any one source" language, which is much of the market.
My PI policy says "series of related matters or transactions" — does Spire apply to me? Spire itself does not (your aggregation wording is the Woodman wording). But the reasoning still informs how a court will read your wording — both decisions sit in the same case law family.
What is the difference between "originating cause" and "series of related matters" aggregation? "Originating cause" looks upstream for the single root of the losses; it aggregates broadly. "Series of related matters" looks for an intrinsic connection between the matters or transactions themselves; it aggregates more narrowly. Spire applies the first; Woodman the second.
Can I negotiate the aggregation wording at renewal? Sometimes. In sectors outside the SRA Minimum Terms regime, broker negotiation can move you between aggregation models — for example to "each and every claim" cover, often at significant additional premium.
If my firm has a partner with a complaints history, do I have to disclose it under s.3? Yes — it is paradigmatically material. Spire makes the point unanswerably. Failure to disclose a known pattern is the cleanest possible breach of s.3 with the strongest possible insurer remedies under Schedule 1.
Does Spire mean my insurer can always aggregate big clusters of claims? Only if your wording is broad enough. Read the wording. If the wording is narrower, Woodman governs and the insurer's argument is harder. The wording is the gatekeeper.
Does Spire affect my supervisory obligations? Spire itself does not change regulatory supervision rules, but it raises the financial stakes of supervisory weakness. A firm whose supervisory model is weak is buying both a regulatory exposure and an insurance exposure.
Sources
- Spire Healthcare Ltd v Royal & Sun Alliance Insurance Plc [2018] EWCA Civ 317 — Court of Appeal judgment on Bailii at https://www.bailii.org/ew/cases/EWCA/Civ/2018/317.html
- Spire Healthcare Ltd v Royal & Sun Alliance Insurance Plc [2016] EWHC 3278 (Comm) — first-instance judgment of HHJ Waksman QC.
- AIG Europe Ltd v Woodman & Others [2017] UKSC 18.
- Insurance Act 2015, sections 3, 7 and Schedule 1.
- Department of Health and Social Care, Report of the Independent Inquiry into the issues raised by Paterson (HC 31, 4 February 2020).
- Lloyd's Market Association aggregation guidance, current edition.
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.