When more than one professional contributes to a client's loss — an accountant and an IFA advising jointly on an investment, an architect and a structural engineer on a building, a solicitor and a surveyor on a conveyance — the law has to decide who pays what. Three regimes are in play: joint liability, several liability, and joint-and-several liability. Each has a different effect on how a claim is brought, how it is defended, and how a professional indemnity policy responds.
Joint liability arises where two or more people share a single duty and cause a single, indivisible loss. Historically a claimant could sue any one of them for the whole loss, and a judgment against one released the others. The regime is now rare in professional contexts — it survives mainly in partnership and agency settings.
Several liability arises where each professional owes a separate duty and each breach contributes to the same loss. The claimant sues each defendant for that defendant's share only. Several-only is the position professionals often prefer, because exposure is capped at the professional's own responsibility.
Joint-and-several liability is a hybrid. Each defendant is liable for the full loss, but a claimant may recover only once. In practice the client sues whichever defendant is most convenient — or most solvent — and that defendant then seeks a contribution from the others under the Civil Liability (Contribution) Act 1978.
Absent an express contractual carve-out, professional team members will usually be several-liable in contract (each engagement letter creates a separate duty) but joint-and-several in tort where their negligence has combined to cause an indivisible loss. Ministry of Housing and Local Government v Sharp [1970] 2 QB 223 is the classic authority for joint tortfeasor treatment where two parties' negligence combines to produce a single harm. Where each professional owes an independent duty of care and each has breached it, the client may sue either for the whole amount.
The Civil Liability (Contribution) Act 1978 then allows the defendant who has paid to recover a just and equitable contribution from the others. Section 2 directs the court to apportion by reference to each party's responsibility for the damage.
Engagement letters and industry standard forms routinely modify the default. The RIBA Standard Professional Services Contract 2020 includes a net-contribution clause that caps the architect's liability at the sum that would be just and equitable having regard to the other consultants' responsibility, assuming they had paid their share. Similar language appears across ACE, RICS and ICE appointments. JCT contract options offer several routes to allocate risk between employer, contractor and consultants, and the JCT Design and Build 2016 places the entire design obligation on the contractor.
Three variations recur:
Under joint-and-several liability, one insurer may pay the client in full and then subrogate against the other professionals — recovering a contribution from their insurers under the 1978 Act. The professional whose insurer paid still uses the aggregate limit and still notifies the loss on renewal.
Under several-only, each professional's insurer responds to that professional's share. The claim is smaller for each policy and each insurer defends its own client. This is generally preferable from the professional's point of view, but the drafting matters — some purported carve-outs have been narrowly construed by the courts.
In a design-and-build procurement the contractor takes single-point responsibility to the employer for both design and workmanship. IBA v EMI Electronics (1980) 14 BLR 1 confirmed that where a contractor undertakes design as well as construction, the contractor owes a duty of fitness for purpose in the absence of clear words to the contrary. Sub-consultants and subcontractors owe their duties to the contractor rather than the employer, and their PI cover responds to the contractor's claim against them.
Worked example — illustrative only. A client suffers a £400,000 investment loss. An accountant and an IFA both advised on the strategy. The court finds joint tortfeasors and apportions 60% to the accountant and 40% to the IFA.
Under joint-and-several liability the client may sue either professional for the full £400,000. If the client sues the accountant, the accountant's PI insurer indemnifies £400,000, then recovers £160,000 from the IFA under the 1978 Act — usually via the IFA's PI insurer.
If several-only liability was expressly agreed in each engagement, the client sues each professional for their share: £240,000 from the accountant and £160,000 from the IFA. Each PI policy responds separately for its share. No subrogation between insurers is needed.
See Apex's pillars on PI insurance for accountants, PI insurance for IFAs, PI insurance for architects and PI insurance for surveyors. Companion wiki entries: Civil Liability (Contribution) Act 1978 and net-contribution clauses in JCT 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.