A consulting engineer signs off a structural calculation for a steel mezzanine in a distribution warehouse. Two years later a forklift loaded above the floor's stated capacity tips a section of decking, the operator is injured, and the warehouse owner discovers that the calculation underpinning the design was wrong by a meaningful margin. The owner's solicitors send a letter before action. The claim — for remedial works, business interruption while the warehouse is partially shut, and a contribution to the operator's injury claim — totals around £620,000.
The engineer did not steal anything. The engineer did not act dishonestly. The engineer made a professional mistake, and a third party suffered financial loss as a result. That is the territory Professional Indemnity Insurance is designed to cover, and the difference between a practice that holds it properly and a practice that does not is the difference between a livelihood that continues and a livelihood that does not.
This guide is for principals at UK professional firms — accountants, solicitors, architects, engineers, surveyors, IT consultants, financial advisers, designers, management consultants — and for sole practitioners and finance directors who want to understand what PI insurance actually does, who needs it, how much is enough, and where the choices that matter at renewal really lie. It runs longer than most online explainers because the detail matters. A generic answer can leave a practice carrying cover that does not respond when the claim arrives.
What Professional Indemnity Insurance is, in plain English
Professional Indemnity Insurance — usually shortened to PI or PII — is a contract between your business and an insurer under which the insurer pays the legal costs of defending a civil claim made against you by a client or third party who says they have suffered financial loss because of professional services you provided, and pays any damages or settlement awarded against you up to the limit of the policy.
The two key ideas worth pulling out: it covers "civil" claims (the other person sues you for money), not regulatory fines or criminal prosecutions; and it covers "professional services" — the advice, design, calculation, opinion or recommendation you give, rather than the physical work of installing or building something.
PI is sometimes called Errors and Omissions cover (the American name) or Professional Liability cover. In the UK the dominant term is Professional Indemnity, and it is the term used in the FCA Handbook and in the rulebooks of the major UK regulators of professional services.
A typical PI policy in 2026 covers:
- The legal costs of defending the claim, including solicitors' fees, counsel's fees, expert witness fees, and court fees
- Damages awarded against you by a court or agreed in settlement
- Claimant's costs awarded against you under English court rules
- Mitigation costs in some wordings — money you spend rectifying the problem before a formal claim arises, with the insurer's consent
- Loss of documents — the cost of recreating client records you have lost or destroyed
- Dishonesty of employees — claims arising from the dishonest conduct of an employee, although usually not of the principals themselves
A typical policy does not cover:
- Regulatory fines, penalties, or sanctions imposed on you by your professional body or by a statutory regulator
- Disputes about your own fees (those are generally outside PI, though they become PI when the client counterclaims on the underlying work)
- Bodily injury or property damage arising from your physical activities — that is what Public Liability cover is for
- Damage to your own property or premises — that is what Office or Commercial Property cover is for
- Employee injury claims — that is what Employers' Liability cover is for
- Liabilities you have voluntarily assumed beyond your common-law and statutory duties — for example, broad indemnities in a contract that go beyond what you would otherwise owe
The boundary between PI and other covers is not always intuitive and is one of the most common areas of policyholder confusion. An IT consultant who advises on a software implementation that fails has a PI claim. The same consultant who drops a server while installing it has a Public Liability claim. The same consultant whose employee is injured installing the server has an Employers' Liability claim. The same incident can in principle implicate more than one policy, and the way the wordings interact matters.
Who needs PI insurance in the UK
PI insurance is required by some professionals as a matter of regulation, and is a commercial necessity for many others even where it is not strictly compulsory.
Regulated professionals who are required to hold PI by their professional body or statutory regulator include solicitors (under SRA Indemnity Insurance Rules — the SRA Minimum Terms and Conditions are mandatory), barristers (under Bar Council requirements through BMIF), accountants in practice with ICAEW, ACCA, ICAS, AAT or CIOT (each body sets its own minimum), architects on the ARB register (under ARB's PII criteria), surveyors with RICS (under the RICS Minimum Approved Policy Wording), insurance brokers (under FCA rules), patent and trade-mark attorneys (under IPReg), licensed conveyancers (under CLC rules), regulated financial advisers (under FCA rules), and members of various other professional bodies. The Engineering Council does not centrally mandate PI for chartered engineers, but the institutions (ICE, IStructE, IMechE, IET and others) include PI as an expectation of practice in their codes of conduct, and most clients require it contractually.
Professionals who hold PI as a contract requirement rather than a regulator requirement include management consultants, IT consultants, designers, marketing and PR agencies, training providers, recruitment consultants, project managers and many others. The dynamic is that an end-client — particularly a public-sector client, a financial-services client, or a regulated business — will require PI as a precondition of contract and will specify the minimum limit (typically £1m, sometimes £2m or £5m). Without the cover, the contract does not happen.
Professionals who hold PI without being either regulated or contractually required to do so because the exposure is real. A small design agency might earn £200,000 a year and have no client who has ever insisted on PI. A single claim from a brand identity that infringed a third party's trade mark, or a website design that produced an accessibility complaint under the Equality Act 2010, can produce six-figure exposure that wipes out years of profits. The economic case for cover does not depend on the regulator.
If you are uncertain whether your activities require PI, the simplest test is: do you give advice, opinion, design or recommendation that a client relies on, and could a reasonable client be financially worse off if you got that advice, opinion, design or recommendation wrong? If yes, PI is relevant; if not, it probably is not.
Claims-made — the most important phrase in the policy
Almost all UK professional indemnity policies are written on a "claims-made" basis. This is the most important phrase in the policy, and the most commonly misunderstood.
A claims-made policy responds to claims that are first made against you, and notified to the insurer, during the policy period — regardless of when the alleged work was done. A claim about advice you gave in 2018, notified to insurers in 2026, is dealt with by your 2026 policy.
The alternative — "occurrence" cover — responds to events that occurred during the policy period, regardless of when the claim is made. PI is almost never written on an occurrence basis in the UK; some general liability covers (Public Liability, Employers' Liability) are.
The practical consequences of claims-made cover are substantial and shape almost every PI decision a firm makes:
You need continuous cover. A gap in cover — a policy that lapses for a fortnight between two insurers — means any claim notified during that gap is uninsured, even if the underlying work was done during a previous insured period.
The policy in force when you notify the claim is the one that pays. Not the policy in force when you did the work. This makes the limit of indemnity on your current policy the limit that matters, not the limit you happened to be carrying in the year you took on the engagement.
Retroactive date matters. The "retroactive date" on the policy defines how far back the cover goes. A retroactive date of 1 January 2018 means the policy will respond to claims about work done after 1 January 2018; it will not respond to work done before that. Most professionals carry a retroactive date that extends back to when they first held PI cover, often described as "full" or "unlimited" retroactive cover.
When you stop trading, your cover ends. Once you wind down, retire, sell the firm, or merge into another, your current policy will not renew. Without "run-off" cover, you have no protection for the long tail of potential claims about work you did when in practice.
We unpack the practical implications of claims-made cover further in our renewal-time piece, PI insurance renewal — what to check before you sign, and the underlying terminology in our PI insurance glossary.
How much cover do you actually need?
The honest answer is: it depends on your worst-case engagement, your sector's claim severity patterns, and what your regulator or contracts require. There is no flat "small firm should buy £X" answer that is correct for every practice, and any explainer that gives one is over-simplifying.
The way to think about it is in three layers.
Layer one — the regulatory or contractual floor. What is the minimum amount your professional body or your client contracts require? For SRA-regulated solicitors this is £2m (for sole practitioners and partnerships) or £3m (for incorporated practices); for ICAEW accountants this is £2m (any one claim and in the aggregate, with a per-firm calculation against gross fee income); for RICS surveyors it scales with turnover up to £1m; for ARB architects it scales with fee income up to £1m; for FCA-regulated mortgage and insurance intermediaries the floor is set by IPRU-INV and depends on income. For unregulated professionals it is often £1m or £2m as a contract demand from end-clients.
Layer two — your worst-case exposure on the engagements you actually take on. Walk through your three or four largest live engagements. What is the value of the transaction, the building, the system, the advice, the design that you are signing off across each? Your PI limit should comfortably exceed the realistic worst-case financial exposure on the most exposed engagement, with headroom for defence costs. Defence costs on a contested PI claim regularly run to six figures, and on complex multi-party disputes can exceed the underlying damages.
Layer three — the cost-versus-protection trade-off. PI premiums are not linear with cover. The price of £2m of cover is not twice the price of £1m. Across most professions and most insurers, the marginal cost of stepping up from £1m to £2m is typically 30%-50% additional premium; stepping again to £5m is a further 40%-70%; stepping further is non-trivial but rarely catastrophic. The protective value of higher cover is significant. Most practices that lose a claim discover, with hindsight, that they should have bought more.
The shape of the limit matters at least as much as its size. A £1m policy on an "any one claim" basis with no aggregate cap is a very different product from a £1m policy "in the aggregate" — and is in turn different from a £1m policy with a separately stated defence-costs sub-limit. We deal with that distinction in detail in our cluster piece, aggregate vs each-and-every claim limit explained.
What a PI claim actually looks like
The popular image of a PI claim is a single dramatic event that a third party sues over. The reality is more varied and more procedural. A typical PI matter unfolds over months, sometimes years, and the policyholder's actions in the first few weeks are often what determine whether the policy responds.
The lifecycle:
Circumstance arises. A client raises a concern about your work, or you become aware internally that something may have gone wrong. There is no claim yet, but there is a circumstance that may give rise to one. This is the moment at which the policy's "notification of circumstances" provision is engaged. Most claims-made wordings require you to notify circumstances as well as actual claims, and require you to do so as soon as practicable after the firm becomes aware of them.
Notification. You notify your broker, who notifies the insurer, of the circumstance. The insurer opens a file but does not necessarily appoint solicitors yet. Notification protects your cover: a circumstance properly notified during the policy year is "ring-fenced" against that year's policy, so a claim that crystallises later — even after you have moved insurer — is still dealt with by the policy that received the notification.
Letter of claim. The client (or their solicitors) writes formally setting out the complaint. The Civil Procedure Rules Pre-Action Protocol for Professional Negligence applies in many cases and requires a structured exchange of letters before any proceedings are issued. The insurer will appoint panel solicitors at this stage, and the client (you, in this case) cooperates with the defence.
Investigation and quantum. Defence solicitors investigate the file, take statements, instruct expert witnesses where needed (a peer professional opining on whether the standard of care was met), and form a view on liability and quantum. Insurers and policyholders make settlement decisions on the basis of this advice.
Resolution. Most professional negligence claims settle without proceedings being issued, often after expert reports are exchanged. A minority go to trial. Settlement may be by payment, by negotiated reduction of fees, by a service-credit, or by a mediated agreement. The policy responds to the settlement up to its limits, after the excess.
Three things in this lifecycle are within the policyholder's control and matter enormously.
The first is prompt notification. Late notification is the most common reason a PI claim fails to be covered. Insurers' wordings vary in how strict they are, but all require notification within a reasonable time and during the current policy period. Carrying a circumstance into a renewed year without notifying the previous insurer is the single biggest avoidable PI mistake.
The second is document control. The defence stands or falls on the file. Practices with disciplined file-management — engagement letters, scope letters, change-of-scope notes, signed minutes — defend claims more cheaply and more successfully than practices whose files are sparse.
The third is honest engagement with the insurer. The insurer is on the same side as the policyholder. Concealing a circumstance, or downplaying a fact pattern in the renewal proposal, is what destroys cover; transparent engagement is what preserves it.
Run-off — the cover you forget about until you stop trading
If you wind down your practice, retire, or sell the firm, your liability for the work you did while in practice does not vanish. Under English contract law the standard limitation period for breach of contract is six years (and twelve years where the contract is executed as a deed, which is common in construction and some commercial engagements). The limitation period for negligence runs from the date of damage rather than the date of the act, and the Latent Damage Act 1986 provides additional time in some cases.
In plain terms: claims about work you did this year can be made against you for at least six years, often longer.
Because PI is claims-made, your last live policy is the last policy that will respond — unless you buy run-off cover. Run-off is PI cover bought after you cease practice, designed to respond to claims about work you did during the practice years.
Most professional bodies mandate run-off for their members:
- The SRA requires solicitors to buy six years' run-off from a "qualifying insurer" when a firm closes (with the Solicitors Indemnity Fund providing post-six-year tail cover in some cases).
- ICAEW requires at least two years of compliant run-off, with the firm taking "all reasonable steps" to maintain cover for a further four years — six in total.
- ACCA requires six years' run-off outright.
- ARB recommends six years' run-off, with longer for projects executed as deeds (typically twelve years).
- RICS requires six years' run-off cover for firms ceasing to practise.
Run-off is normally purchased as a single up-front premium, often calculated as a multiple of your last year's working premium (commonly 100% to 250% of the working premium, spread across the run-off period in aggregate, varies materially by sector and insurer). It is one of the easiest things to overlook when planning to retire and one of the most expensive to fix retrospectively. Buying it is non-negotiable for most regulated professionals.
We cover the practical structure of run-off in more detail in the PI insurance glossary and at renewal in PI insurance renewal — what to check before you sign.
How premiums are calculated — what the insurer is looking at
PI underwriting is not a black box but is also not formulaic. Underwriters at the major UK PI insurers look at a defined set of inputs to price your renewal, and a sensible renewal submission addresses each of them clearly.
Fee income. The headline rating factor. Larger practices generate more activity and more potential for claims, and pay accordingly. The premium curve is sub-linear — a firm earning twice as much does not pay twice the premium — but it is meaningfully tied to income.
Fee income split by activity. Different professional activities carry different loss expectations. Tax advice carries higher loss costs than accounts preparation. Audit carries higher loss costs than tax advice. Conveyancing carries higher loss costs than will-writing. Design-and-build architecture carries higher loss costs than traditional contract administration. The underwriter wants the split.
Claims and circumstances history. Five years of claims, notifications and circumstances is the standard ask. Clean histories price cleanly; notified circumstances or paid claims push the premium up and may make some markets reluctant to quote.
Sector and client mix. Acting for high-risk clients (listed companies, financial services firms, public sector bodies, foreign-domiciled clients in some cases) raises the underwriter's loss expectation.
Internal risk management. File reviews, peer review programmes, quality control procedures, CPD compliance, the methodology software you use, the engagement-letter discipline you operate. Underwriters cannot inspect every firm but they pay attention to the answers in the proposal form.
Limit of indemnity, excess, and policy structure. Higher limits cost more (sub-linearly). Higher excesses reduce premium. Wider extensions (cyber, dishonesty, defamation, contract works) typically add premium. Layered structures spread risk between primary and excess insurers and become cost-effective at higher total limits.
Market conditions. The PI market cycles — periods of "soft" market with falling premiums and broader cover, and periods of "hard" market with rising premiums and tighter cover. The architects' and solicitors' markets were materially hard in the early 2020s and have softened in 2025-26; the IT and cyber-adjacent professional markets remain more disciplined. Where your renewal falls in the cycle matters.
The role of the broker
PI is a specialist insurance product placed in a specialist market, and the broker's role is to translate between the firm's professional activities and the underwriter's risk framework. In FCA-regulated UK insurance distribution, a broker acts for the client, not for the insurer — that is the regulatory position under FCA Conduct of Business rules — and is paid by commission or fee for placing and servicing the cover.
A good broker, in our experience, does five things at renewal:
First, helps the firm prepare a renewal submission that presents the practice fairly to the underwriter — fee split, claims history with context, risk management, key changes from last year.
Second, takes that submission to insurers whose appetite is likely to match the firm's profile, rather than scattering it across the market.
Third, returns with multiple quotes — usually three or four — set out so that the firm can compare them on more than headline premium, including wording differences, excess levels, sub-limits and extensions.
Fourth, explains the trade-offs in plain language and makes a clear recommendation.
Fifth, documents the decision so that the firm's own compliance review and the regulator's monitoring (where applicable) have an audit trail.
The broker is also the first point of contact when a circumstance arises during the policy year. Notification is made through the broker, who acts as the conduit to the insurer.
Apex Insurance Brokers is an independent FCA-authorised broker (firm reference 724952). We are not tied to any one insurer, do not run our own policy or our own underwriting, and do not have placement quotas with insurers that would skew our recommendations. Our remuneration disclosure is on our Terms of Business page and the route to raising concerns about our service is on our Complaints page.
Common misconceptions about PI
A handful of misconceptions recur often enough to be worth addressing directly.
"My old policy will cover the old work." It will not. PI is claims-made — the policy in force when the claim is notified is the policy that responds. Your old policy is closed.
"I have a limited company so the directors are not personally exposed." Limited liability protects you from the company's debts in the ordinary course; it does not protect you from professional negligence claims that name you personally, which is increasingly common in tort claims against named principals.
"I have a clean record so I do not need much cover." Past claims history is a poor predictor of future claim severity. The £600,000 claim arrives once, and it is the first one.
"My excess is high so my premium is low." Sometimes — but excess only protects the insurer from low-value attritional claims. A high excess does not reduce your exposure to a serious claim. It only changes who pays the first slice.
"I do not need to notify circumstances, only actual claims." Wrong, and dangerous. Most wordings require notification of circumstances as soon as practicable. Carrying an unnotified circumstance into a renewed year is the most common way to forfeit cover.
"PI is the same as Public Liability." No. PI is for financial loss arising from professional advice. Public Liability is for bodily injury or property damage arising from your physical operations. Both may be relevant; neither substitutes for the other.
What to do next
If you are within ninety days of your PI renewal, this is the moment to look at your existing policy schedule and assess whether the limit, the wording, the retroactive date and the broker relationship are still appropriate. If you are mid-policy, this is the moment to confirm that everything notifiable has been notified.
For broader sector-specific framing, see our sector hub at /sectors/ which links through to dedicated guides for accountants, solicitors, architects, surveyors, IFAs, IT professionals and engineers. For practical renewal preparation, see PI insurance renewal — what to check before you sign. For the terminology, see our PI insurance glossary. If you are Bristol-based, see Professional Indemnity insurance broker in Bristol.
To talk through your PI position with an Apex broker, contact us. The first conversation costs nothing and does not commit you to anything.
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Frequently asked questions
What is the difference between Professional Indemnity and Public Liability insurance?
Professional Indemnity covers civil claims arising from financial loss a client or third party suffers because of your professional advice, design, opinion or recommendation. Public Liability covers civil claims for bodily injury or property damage arising from your physical activities or business premises. The same firm often needs both. A management consultant whose advice leads to a £400,000 client loss has a PI claim; the same consultant whose visitor trips on a loose office cable and breaks a wrist has a Public Liability claim. The wordings do not overlap meaningfully and one does not substitute for the other.
Is PI insurance compulsory in the UK?
It depends on your profession. PI is compulsory for solicitors (SRA Indemnity Insurance Rules), barristers, accountants in practice with ICAEW, ACCA, ICAS and AAT, architects registered with ARB, RICS surveyors, FCA-regulated insurance brokers and financial advisers, licensed conveyancers, regulated patent and trade-mark attorneys, and various other regulated professions. For unregulated professional activities — design consultancy, IT consultancy, marketing, training, project management — PI is not legally compulsory but is almost always required by end-clients as a precondition of contract, and is a commercial necessity.
What does "claims-made" mean and why does it matter?
A claims-made policy responds to claims first made against you, and notified to the insurer, during the policy period — regardless of when the alleged work was done. The current policy is what responds to a claim about work done in any earlier year, provided the retroactive date covers the older work and continuity has been maintained. This means continuous cover, prompt notification of circumstances, and proper run-off cover when you cease practice all matter substantially. A gap in cover, or a circumstance not notified before the policy year ends, can leave a claim uninsured even though the work was done during an insured period.
How much PI cover do I need?
The minimum is set by your regulator or your contract — for SRA solicitors £2m or £3m, for ICAEW accountants £2m (or 2.5x gross fee income if smaller), for RICS surveyors a turnover-banded scale up to £1m, for ARB architects a fee-banded scale up to £1m, and for many unregulated professionals £1m or £2m as a contract demand. The amount actually right for your practice depends on the worst-case financial exposure on your largest engagements, with headroom for defence costs. Most practices that lose a claim wish, with hindsight, that they had bought more. The marginal cost of higher cover is usually modest relative to the protection it provides.
What is run-off cover and when do I need it?
Run-off is PI cover bought after you cease practice, designed to respond to claims about work you did while in practice. Because PI is claims-made, your last live policy is the last policy that will respond once you stop paying premiums — unless you buy run-off. Most professional bodies mandate it: six years for SRA solicitors, six years for ACCA accountants, two-to-six years for ICAEW accountants, six years for RICS surveyors, and six years recommended by ARB for architects (longer for deed-executed contracts). Run-off is normally a single up-front premium calculated as a multiple of your last working premium.
What happens if I do not notify a circumstance during the policy year?
If a circumstance that could give rise to a claim arises during the policy year and you do not notify it, you risk losing cover for that claim entirely. Carrying an unnotified circumstance into a renewed policy is one of the most common reasons a PI claim fails to be covered, because the new insurer will say the circumstance pre-dated cover and should have been notified to the previous insurer, while the previous insurer says it was not notified before that policy ended. The safe rule is to notify any circumstance you become aware of as soon as practicable, even if you are unsure whether it will crystallise into a claim. Notification does not commit you to anything but preserves cover.
Will my PI premium go up if I make a claim?
Possibly, and it depends on the size of the claim, the underlying fact pattern, and the underwriter's view at renewal. A circumstance that closes out without crystallising usually has little long-term effect on premium. A settled claim, particularly above the policy excess, typically does affect renewal pricing and may make some markets reluctant to quote. A broker's role at renewal includes presenting the history fairly so it is not perceived more harshly than it deserves. The premium impact of a claim is usually less severe than firms fear and is most pronounced in the first renewal after the claim.
Can a sole practitioner buy PI insurance?
Yes. The UK PI market writes policies for sole practitioners across most regulated and unregulated professional activities. Premiums for sole practitioners are scaled to their lower fee income and are typically in the low-four-figure to mid-four-figure range for £1m to £2m of cover, depending on the activity, the sector, and the claims history. Some specialist activities — financial advice, audit, design-and-build architecture — cost more even at sole-practitioner scale because the underlying claim severity expectation is higher.
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Related guides
- Aggregate vs each-and-every claim limit explained
- PI insurance renewal — what to check before you sign
- PI insurance glossary
- Professional Indemnity insurance broker in Bristol
- Sectors hub — speak to a specialist
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About Apex Insurance Brokers — Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority, FCA firm reference 724952. Registered in England and Wales, Companies House 07014570. Last reviewed: May 2026.
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