PI & contract law · Liability caps
PI insurance and terms-of-business liability caps — how the two interact
Reviewed by Matthew Bartlett, Director, Apex Insurance Brokers Limited · Published 14 July 2026
Professional firms routinely include liability caps in their terms of business or engagement letters. But a liability cap is not the same as PI insurance — they do different jobs, and they interact in specific ways. This page explains what caps do, what they can't do, and how they should be sized against the PI position.
The two protections
- Liability cap. A contractual limit on the firm's exposure to a specific client under the engagement contract. Sits inside the client contract, not the insurance policy.
- PI insurance. The insurer indemnifies the firm for civil liability up to the policy limit, subject to wording.
Different purposes: the cap limits the firm's legal exposure; the insurance funds the exposure that survives the cap.
What a liability cap does
- Limits the firm's contractual liability to the specific client for that engagement.
- Typically expressed as a multiple of fees paid, or a fixed sum, or the greater of the two.
- Enforceable in most UK commercial contracts subject to the Unfair Contract Terms Act 1977 for consumer contracts and to reasonableness for B2B.
- Does not affect claims from third parties who are not party to the contract.
- Does not affect regulatory claims from professional bodies.
What a liability cap does not do
- Does not protect against professional-body regulatory action.
- Does not protect against claims from third parties (non-clients).
- Does not survive if the client can show fraud or wilful misconduct.
- Cannot cap for personal injury or death.
- Consumer clients (individuals acting in personal capacity) have significant statutory protection under UCTA and Consumer Rights Act 2015 — caps may not enforce.
- Does not automatically apply to secondary claims (indemnity claims, contribution claims from co-defendants).
How the cap interacts with PI
- Cap survives, PI responds. Firm pays up to cap; insurer indemnifies the firm for the payment (subject to wording).
- Cap struck down, PI responds fully. Court finds the cap unenforceable; firm faces full liability; PI responds up to policy limit.
- Cap is much higher than PI limit. Cap doesn't actually limit anything; PI is the real ceiling.
- Cap is much lower than PI limit. Firm efficient use of PI — but check that the cap actually enforces in the specific contract.
- Multiple claims aggregating. Cap applies per contract; PI aggregation applies across contracts. Interaction requires structural review.
Sizing the cap
- Fees-multiple caps typically 2x to 10x fees paid; higher for higher-fee, higher-risk work.
- Fixed-sum caps typically £100k to £5m depending on engagement.
- Cap should be commensurate with the client's reasonable expectation of protection and the firm's reasonable expectation of exposure.
- Unreasonably low caps face UCTA challenge; unreasonably high caps offer little protection.
- Some engagements have specific regulatory floors (SRA restricts caps for certain client-facing work).
Cap language to look for
- Clear numeric cap — explicit sum or multiple.
- Exclusions from the cap — typically fraud, wilful misconduct, personal injury.
- Application — per engagement, per client, per year.
- Interaction with indemnity provisions.
- Time limits — some caps are structured with time-limited enforcement periods.
Where caps fit alongside PI structure
- Small commercial firm. Cap at 3-5x fees; PI at £2m per claim. Cap catches the client-facing exposure; PI catches third-party and cap-strike-down scenarios.
- Mid-market professional firm. Cap at £1m-£5m fixed; PI at £5m each and every. Layered protection.
- Large firm with material client-value. Cap at £5m-£25m; PI programme at £10m-£50m. Cap provides negotiation leverage; PI provides the real financial protection.
Frequently asked
Can I just use a liability cap in my contract and skip PI insurance?
No, for several reasons: (1) Liability caps don't protect against third-party claims; (2) Some regulators (SRA especially) require PI regardless of client contract terms; (3) Caps face enforceability challenges under UCTA and can be struck down; (4) PI covers scenarios (regulatory investigation, criminal defence) that contracts cannot.
Are liability caps enforceable in UK B2B contracts?
Generally yes, subject to reasonableness under UCTA 1977. Consumer contracts face significantly higher scrutiny under Consumer Rights Act 2015. Even in B2B, caps that are commercially unreasonable can be struck down.
What is a fair liability cap for a £10,000 engagement?
Fees-multiple caps of 3x to 10x fees are common in the market. For a £10,000 engagement, that suggests £30k to £100k cap. But the reasonable number depends on the client's reasonable expectation of protection given the value of the underlying transaction.
Does the SRA restrict liability caps for solicitors?
Yes for some client-facing work. SRA rules restrict how solicitors can limit liability to clients, particularly consumer clients. Some contractual limitations that would be enforceable in commercial contracts do not enforce for SRA-regulated work.
If my client's claim exceeds the cap, does PI still respond up to policy limit?
Depends on wording and specifics. Where the cap is enforceable and applies, the firm's liability is the cap; PI indemnifies the firm for that liability. Where the cap is struck down, the firm faces full liability; PI responds up to its policy limit.
Should my liability cap match my PI limit?
Not necessarily. The cap is a contract term; the PI limit is the ultimate financial protection. Some structures have the cap lower than PI limit (firm bears more risk if cap enforces; PI carries excess if cap fails); others reverse. Discuss with legal advisor.
Can I have a cap that says liability is only the fee paid?
In commercial B2B contracts yes in principle, subject to reasonableness. In consumer contracts, materially harder to enforce. In regulated professional services, may face additional regulatory scrutiny.
Does a cap protect me against professional-body regulatory action?
No. Regulatory investigations and disciplinary proceedings sit outside the client contract. Liability caps do not bind the regulator. PI cover with regulatory investigation extension is the relevant protection.