Cover sizing · PI
Is my PI cover limit enough? The five-step adequacy check
Reviewed by Matthew Bartlett, Director, Apex Insurance Brokers Limited · Published 14 July 2026
‘How much cover do I need?’ is the most common PI question. There is no single number that fits every firm — but the framework for arriving at your number is stable across professions. This page is the five-step adequacy check.
Step 1 — the regulatory floor
Start with what your regulator requires.
- SRA (solicitors): £2m per claim sole practitioner / partnership; £3m per claim incorporated. Each-and-every-claim structure.
- ARB (architects): adequate to the practice — qualitative.
- ICAEW (accountants): 2.5x fee income, £100k minimum, £5m maximum per claim.
- RICS (surveyors): turnover-band scale from RICS guidance.
- FCA-authorised firms: MIPRU/ICOBS minimums (€1.3m per claim / €1.9m aggregate).
- Non-regulated professional firms: no floor; commercial decision.
Step 2 — worst-case single-claim exposure
Regulatory minimum is a floor, not a target. The real question is: what is the plausible maximum single-claim exposure your firm could face?
- Deal value or project value: largest single matter you've worked on in the last 12 months, or plan to work on.
- Loss multiplier: how the claim quantum could exceed the underlying deal value (consequential losses, follow-on damages, defence costs).
- Client type: whether affected parties would be sophisticated corporate claimants or retail consumers.
- Aggregation potential: whether multiple related matters could aggregate into a single loss.
A useful heuristic: take your largest single deal/project of the last three years and consider a plausible worst-case loss scenario. Your cover limit should comfortably exceed that with room for defence costs.
Step 3 — aggregation and multi-claim exposure
Aggregate cover exhausts across the policy year. Multiple related claims can pancake into single aggregation events and drain the limit fast.
- Portfolio-scale exposure: how many client relationships could be affected by a single systemic failure (template error, process weakness).
- Aggregation clause: how the wording treats multiple related losses.
- Reinstatement provisions: whether the limit reinstates after the first aggregation.
- Each-and-every-claim vs aggregate: which structure the policy uses.
Step 4 — tail-liability exposure
PI is claims-made. The relevant limit is the limit at the time the claim is made, not when the work was done. Long-tail exposures require long cover.
- Limitation period: professional negligence typically six years from breach or discoverability.
- BSA 2022 s.135 for architects and construction consultants: 30 years pre-June-2022, 15 years going forward.
- DB-transfer historic advice for IFAs: FCA continued focus.
- Retro-date on current policy: how far back cover extends.
- Run-off requirement on cessation: what limit is needed for the tail.
Step 5 — personal exposure of partners and principals
Where the firm structure creates personal liability (partnership, LLP with member liability, sole practitioner), the individuals' personal balance sheets are effectively part of the PI conversation.
- Partnership: each partner potentially personally liable for the firm's debts including PI-exposed liabilities.
- LLP: limited personally except in narrow circumstances, but members' capital and drawings still at risk in an inadequately-covered claim.
- Sole practitioner: full personal exposure.
- Incorporated practice: corporate veil protects individuals subject to statutory duties.
Cover limit sizing should protect not just the firm but the individuals whose personal assets sit behind it.
Putting it together — a worked example
- Firm: small solicitors' practice, mixed conveyancing / probate / commercial.
- Regulatory floor: SRA MTC minimum £2m per claim.
- Worst-case single-claim: high-value conveyance £800k property, plausible loss including consequential and defence £1.5m.
- Aggregation: multiple related conveyancing errors could aggregate — potentially 3-5 matters into a single loss £5m+.
- Tail: standard six-year professional negligence limitation plus any BSA-touching conveyance (higher-risk buildings) with 30-year tail.
- Personal: two-partner traditional partnership, personal exposure.
- Reasonable cover conclusion: £5m each and every, aggregate reinstated, with extended retro-date. Above the SRA floor, appropriate to the practice profile.
This is illustrative — every firm's number depends on its specifics. A specialist broker's job is to work through the framework with the firm and arrive at a defensible number.
Frequently asked
What is the minimum PI limit I need in the UK?
Depends on regulator. SRA solicitors: £2m/£3m per claim. ARB architects: adequate to practice. ICAEW accountants: 2.5x fee income, £100k-£5m range. FCA-authorised firms: MIPRU/ICOBS minimums. Non-regulated: no floor. The minimum is a floor, not a target.
How do I calculate my worst-case single-claim exposure?
Take your largest deal or project of the last three years, consider plausible loss multiplied by consequential and defence costs. This is your worst-case single-claim number. Compare against your current limit.
Should I add extra cover above the regulator's minimum?
In many cases yes. The regulator's minimum protects the client and the profession, not the firm's balance sheet. Prudent cover often sits materially above the floor.
What is aggregation and why does it matter for limit sizing?
Aggregation is the wording provision that treats multiple related claims as a single loss for policy-limit purposes. It matters because a template error affecting 50 clients aggregates to one loss under many wordings — and an aggregate limit set to worst-case single claim may be exhausted.
How does BSA 2022 affect architects' limit sizing?
It extends limitation for higher-risk-building work. Cover must be adequate to a longer tail. Sizing needs to reflect not just today's exposure but the plausible worst-case emerging over the next 30 years for pre-2022 acts.
Do partnership members need more PI than LLP members?
Effectively yes. Partnership members face potentially unlimited personal liability; LLP members' liability is limited except in specific circumstances. Cover limit sizing should reflect the practical personal exposure.
Can I be over-insured on PI?
Yes, in a limited sense — paying for cover you'll never need is uneconomic. But most firms are more likely to be under-insured than over-insured, particularly against aggregation and tail risks. Specialist broker input helps calibrate.
Should I hold layered cover with primary and excess insurers?
For firms above £5m-£10m cover requirement, typically yes. Layered programmes are the standard structure for larger professional firms. Specialist broker builds the programme with wording consistency across layers.