Subrogation is one of the foundational doctrines of English insurance law. It gives an insurer that has indemnified its insured the right to step into the insured's shoes and pursue recoveries from any third party whose conduct contributed to the loss. In professional indemnity (PI) insurance, where losses can be substantial and often involve chains of contractors, suppliers, and sub-consultants, subrogation is a routine feature of how claims are ultimately resolved.
Subrogation flows from the indemnity principle. Because an insured is entitled to be indemnified for a loss, but no more than indemnified, any recovery from a third party in respect of that same loss should not leave the insured better off than before. The classic statement is in Castellain v Preston (1883) 11 QBD 380, where Brett LJ described subrogation as a doctrine that prevents the insured from recovering twice and enables the insurer to take the benefit of any right of action or recovery the insured has against a third party responsible for the loss.
The Marine Insurance Act 1906, s.79 puts the equivalent principle on a statutory footing for marine insurance. Although PI insurance is a non-marine class, the courts treat s.79 as reflecting the general common-law position and it informs how subrogation operates across insurance more broadly.
Subrogation gives the insurer two related rights once it has paid the claim.
First, the benefit of the insured's rights of action against third parties. The insurer may bring proceedings in the insured's name against, for example, a negligent sub-contractor, a defective goods supplier, or another professional whose breach contributed to the client's loss. The action remains in law the insured's; the insurer is the party with the economic interest and, typically, the party controlling the litigation.
Second, the benefit of any recoveries the insured obtains in respect of the loss. If the insured receives money from a third party after being indemnified, the insurer is entitled to that money up to the amount it has paid out. This prevents the double-recovery the indemnity principle forbids.
The House of Lords in Napier and Ettrick (Lord) v Hunter [1993] AC 713 confirmed that the insurer's interest in subrogated recoveries is protected by an equitable lien over the sums received by the insured. If the insured collects money from a third party in respect of the indemnified loss, the insurer's proprietary interest attaches to those funds. The insured holds the recovery, to the extent of the insurer's payment, on constructive trust and cannot dissipate it or prefer other creditors ahead of the insurer.
Most PI policies contain express subrogation wording, which typically clarifies and sometimes extends the common-law position. A standard clause confirms the insurer's right to take over and conduct in the insured's name the defence or settlement of any claim, and the pursuit of any recovery. Clauses commonly require the insured to give reasonable assistance, sign documents, and refrain from prejudicing the insurer's recovery rights.
Both at common law and under the policy, the insured owes duties that support the insurer's subrogated position. Evidence should be preserved: correspondence, drawings, specifications, site records, and electronic files that may bear on third-party liability should not be destroyed. The insured should not settle with, release, or waive rights against a potentially liable third party without the insurer's consent, because doing so may extinguish the very right the insurer would otherwise exercise. Claims-handling standards in the FCA's ICOBS Handbook reinforce fair and prompt handling of claims and expect clear communication when insurers intend to pursue subrogated recoveries.
Contracts sometimes include a waiver of subrogation, under which one party agrees that its insurers will not pursue the counterparty for insured losses. Construction contracts, joint-venture agreements, and some professional appointments contain such clauses. Insureds should raise these with their broker before agreeing them, because a waiver may cut across the policy's subrogation wording and, if not properly notified to insurers, could create coverage issues. Knock-for-knock arrangements in some sectors work on the same principle by allocating risk between parties regardless of fault.
An architect's structural design fails and the client suffers a loss. The PI insurer indemnifies the architect and pays £600,000 to the injured client under the policy. Investigation shows the failure was contributed to 40% by a defective steel product supplied by a specialist supplier and 30% by poor installation by a sub-contractor. The insurer, exercising its subrogation rights in the architect's name, pursues recoveries from the supplier and the sub-contractor. It recovers £180,000 from the supplier and £150,000 from the sub-contractor. The total recovery of £330,000 reduces the insurer's net loss on the claim to £270,000. The architect is not better or worse off; the indemnity principle is preserved; and the parties actually responsible for the underlying defects bear their share.
For sector-specific PI guidance, see Apex's pillar guides on architects' PI insurance, engineers' PI insurance, and surveyors' PI insurance. For related claims concepts, see the Apex wiki entries on the indemnity principle, the insured's duty to cooperate, and waivers of subrogation in construction contracts.
Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Firm reference number 724952. This entry is general information, not advice on any particular policy.