£10 million PI insurance: who needs it and how to buy it

Reviewed by Matthew Bartlett, Director, Apex Insurance Brokers Limited · Last reviewed 2026-08-10

Very few firms wake up one morning and decide they would like £10 million of professional indemnity cover. The limit arrives from outside: a procurement team's minimum requirement, a funder's condition, a warranty schedule in a development agreement. The buying decision is therefore less about appetite and more about engineering — understanding precisely what the contract demands, and assembling cover that genuinely satisfies it rather than merely gesturing at the number.

Where does a £10 million requirement actually come from?

Rarely from a regulator or professional body. The SRA's minimum terms require £2 million any one claim (£3 million for recognised and licensed bodies); RICS, ICAEW and other bodies set minimums that scale with fee income but seldom approach eight figures. Mandatory minimums are a floor, and £10 million sits well above almost all of them.

In practice the requirement comes from four places. First, client master services agreements — large corporates, banks and insurers routinely stipulate PI limits for panel firms and key advisers, and £10 million is a common threshold for substantial mandates. Second, framework agreements and public-sector tenders, where the limit is a pass/fail criterion at PQQ or SQ stage and there is usually little room to negotiate before qualification. Third, collateral warranties and third-party rights on construction and development projects, which typically require the consultant to maintain PI at a stated level for a defined period after practical completion — often twelve years where the appointment is executed as a deed. Fourth, lenders and funders, whose conditions precedent frequently mirror or exceed the employer's own requirements.

Each source produces different drafting, and the drafting matters. A clause that says “£10 million for each and every claim” is a materially different obligation from “£10 million in the aggregate”, and a duty to maintain the limit for years after the work concludes is a different undertaking again — one that survives your ability to know what the insurance market will look like when the time comes. Read the clause before you go anywhere near the market, and if the drafting is genuinely unachievable — unlimited duration, no insolvency carve-out, cover “in respect of this project alone” when your policy is a practice-wide annual aggregate structure — the moment to say so is before signature.

£10 million any one claim or in the aggregate — which do you actually need?

At lower limits the distinction is often academic. At £10 million it is the single most consequential feature of the programme. An any-one-claim (or “each and every claim”) limit restores in full for every separate claim in the policy period; an aggregate limit is a single pot that erodes as claims — and, under many wordings, defence costs — are paid. A firm facing two unrelated £6 million claims in one year is fully protected under the former and significantly exposed under the latter.

Contract drafting usually tells you which is required, though not always clearly — “£10 million professional indemnity insurance” with no elaboration is common and should be clarified rather than assumed. Where a true any-one-claim basis is not available or not proportionate, aggregate cover with one or more reinstatements is a recognised middle position, and many procurement teams will accept it if asked. Be aware, too, that a layered programme can mix bases: it is not unusual for parts of a tower to sit on different terms, and the effective basis of the whole placement is only as good as its most restrictive layer. The mechanics are worth understanding properly — we cover them in detail in any one claim vs aggregate PI.

Aggregation language deserves equal attention. Most wordings treat claims arising from the same originating cause or related acts as a single claim, which at this level cuts both ways: it can preserve a single any-one-claim limit across a cluster of related claimants, or it can compress what felt like several claims into one limit. How a wording aggregates is at least as important as the number on the schedule.

How is £10 million of capacity actually put together?

A single insurer will sometimes write the full limit, particularly for lower-hazard professions, but for many firms £10 million is assembled in layers. A primary insurer writes the first tranche — commonly the first few million — on a full policy wording, and one or more excess-layer insurers sit above it, each attaching where the layer below exhausts. Individual layers may themselves be shared between insurers on a co-insurance or subscription basis, each taking a percentage of that layer.

The primary wording is the foundation of the whole tower. Excess layers are typically written “follow form” — adopting the primary's terms — but the follow is almost never total: excess policies carry their own conditions, their own notification provisions and sometimes their own exclusions, and the differences are where towers fail. The features to scrutinise include whether each excess layer recognises erosion of the underlying limit by defence costs as well as damages; whether the layer drops down if an underlying insurer becomes insolvent (many wordings do not); and whether retroactive dates and continuity of cover are aligned all the way up. A £10 million tower with a misaligned retroactive date in the top layer is, for older work, a smaller tower than it appears. The structural questions are examined further in our guide to excess layer PI insurance.

Layering has genuine advantages beyond necessity: it spreads insurer credit risk, lets each insurer deploy capacity where it is comfortable, and often produces a more resilient placement than a single carrier writing the whole limit reluctantly. But it multiplies the documents, and every document must be read.

What will underwriters ask of a firm buying at this limit?

More than a proposal form. At £10 million, underwriters are pricing severity, and severity lives in the detail of what you do and for whom. Expect the submission to need to cover:

• Fee income by activity and geography — split with enough granularity to show where the higher-hazard work sits, including any US or other overseas exposure.
• Your largest engagements — contract values, the clients behind them, and whether your appointments cap liability or include net contribution clauses.
• Claims and circumstances history — typically across a number of years, with a credible narrative on anything material: what happened, what changed afterwards.
• Risk management in practice — engagement letter discipline, scope-of-work control, peer review and supervision arrangements, how conflicts and lateral hires are managed.
• The people — the experience and qualifications of principals, and how work is resourced, including any use of subconsultants or subcontracted professionals.

Presentation quality is not cosmetic at this level. A well-organised submission that anticipates the underwriter's questions — and, for larger or more unusual risks, a direct meeting between the firm's principals and the lead underwriter — measurably improves both the terms offered and the number of insurers willing to quote. Underwriters at this limit are backing management as much as they are backing a profession.

What should you check before signing off the programme?

Treat the tower as one instrument and test it as a whole. Do all layers share the same retroactive date and, where relevant, the same treatment of prior firms and predecessor practices? Do the notification provisions work together, so that a circumstance notified to the primary is treated as notified for the tower — or does each excess layer require separate notice? Are exclusions consistent, or has an excess insurer introduced a carve-out the primary does not have? Is the basis of cover — any one claim, aggregate, reinstatements — consistent, and does it match what your contracts actually require? Are defence costs payable in addition to the limit or within it, and is that treatment the same at every level?

None of these questions is exotic, but each is routinely missed when a placement is assembled quickly, and each has been the difference between a tower that pays £10 million and one that does not. Where you hold obligations under collateral warranties, check the maintenance period and the standard-of-care language against the policy as well — a warranty that demands more than your policy covers is a gap the certificate of insurance will not reveal.

How should you actually run the purchase?

Start early — materially earlier than an ordinary renewal, because a layered placement involves sequencing: the primary terms must be settled before excess insurers can meaningfully quote, and the excess market will want time. Decide the rationale for the limit before approaching the market: which contracts require it, on what basis, for how long, and whether any of those requirements are negotiable. It is sometimes cheaper to negotiate a contract than to insure it as drafted, and a broker who understands both the market and the drafting can tell you which conversation to have.

Choose a broker with genuine access to the excess and high-limit markets, including where relevant the London market, and who will place the tower as a coherent whole rather than a stack of separate transactions. And treat the limit as a living decision: new frameworks, new warranties and firm growth all move the requirement, and a mid-term review when a significant contract lands is far better than discovering at tender stage that your programme falls short.

Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority (FRN 724952). This article is general information, not advice on a specific policy.