Insuring the Advice Rather Than the Building
Professionals who are paid for judgement face claims that they got it wrong, and general liability insurance does not cover that. Errors and omissions cover exists for the harm caused by work rather than by accidents.
The Gap in Ordinary Liability Cover
A general liability policy covers bodily injury and property damage. If a client trips in your office, it responds.
If you are an accountant whose advice caused a client to overpay tax, an architect whose design specification was wrong, or a consultant whose recommendation cost a client money, no bodily injury or property damage occurred. The harm is purely financial and general liability does not reach it.
Errors and omissions cover, also called professional liability or professional indemnity, fills that gap. It responds to claims alleging that a professional service was performed negligently, causing the client financial loss.
The Trigger Is the Critical Feature
Most liability insurance is written on an occurrence basis, meaning the policy in force when the harm happened responds, even if the claim arrives twenty years later.
Professional liability is almost always written on a claims made basis, meaning the policy in force when the claim is made responds, regardless of when the work was performed.
| Occurrence Basis | Claims Made Basis | |
|---|---|---|
| Which policy responds | The one in force when harm occurred | The one in force when the claim is made |
| Effect of letting cover lapse | Past years remain covered | Past work becomes uninsured |
| Common in | General liability, property | Professional, directors and officers, cyber |
Under a claims made policy, cancelling cover does not end your exposure, it ends your protection. A professional who retires and stops paying premiums has left every piece of work they ever did uninsured against a claim arriving next year.
Retroactive Dates and Tail Cover
Two provisions manage the timing problem and both are frequently misunderstood.
The retroactive date defines how far back the policy will reach. Work performed before that date is excluded entirely, regardless of when the claim arrives. Maintaining continuous cover preserves an early retroactive date; a gap resets it, which can silently eliminate cover for years of past work.
Extended reporting, commonly called tail cover, allows claims to be reported after the policy ends, for an additional premium. It is what a retiring professional or a firm being wound up needs, and it is priced as a multiple of the annual premium.
A firm being sold negotiates over who buys the tail, and the cost is a real line item in the transaction.
Defence Costs Are Frequently the Whole Claim
Most professional liability claims do not result in a payment to the claimant. They result in legal costs incurred establishing that the professional was not negligent.
The policy structure therefore matters enormously. A duty to defend policy obliges the insurer to appoint and pay counsel, which is valuable for a small firm that could not otherwise fund a defence. A duty to indemnify policy reimburses the insured for costs incurred, which preserves choice of counsel and requires the firm to fund the defence first.
Whether defence costs erode the limit is the other decisive term. Under an eroding limits policy, every dollar of legal fees reduces the amount available to settle, so a lengthy defence can exhaust the cover before any settlement is reached. Limits outside costs are more expensive and considerably better.
What Is Excluded
Standard exclusions define the boundary and each has a rationale.
Dishonest or fraudulent acts are excluded, since insuring deliberate wrongdoing would be uninsurable and against public policy. Policies typically defend such allegations until a final adjudication establishes them, which matters because fraud is routinely pleaded alongside negligence.
Contractual liability assumed beyond ordinary professional obligations is excluded, which is why guaranteeing an outcome in a client contract can void cover for the very thing guaranteed.
Bodily injury and property damage are excluded because general liability covers them, and the two policies are designed to fit together without overlap or gap.
Who Requires It
Professional liability is mandatory for several regulated professions, including solicitors and accountants in many jurisdictions, at minimum limits set by the regulator.
Beyond regulation, it is increasingly required contractually. Client procurement processes routinely specify minimum limits, and a supplier without cover at the required level cannot be engaged, which makes the policy a commercial prerequisite rather than merely a risk management choice.
The categories requiring it have broadened well beyond traditional professions to include technology vendors, marketing agencies, recruiters, and anybody delivering a service where a client can allege that failure caused financial loss.
The Bottom Line
Errors and omissions cover exists because the harm a professional causes is financial rather than physical, and no other policy responds to it. Its defining feature is the claims made trigger, which means cover protects you only while you keep paying for it, and which makes the retroactive date and the tail the two most consequential items in the schedule. Defence costs dominate the claims experience, so whether the insurer must defend and whether those costs erode the limit determine what the policy is actually worth.