Professional Indemnity Insurance for Quantity Surveyors and Cost Consultants

Reviewed by Apex Insurance Brokers · Last reviewed 2026-08-05

Why quantity surveyors face a distinct liability

A quantity surveyor (QS) or cost consultant does not simply survey buildings — you advise on money. Cost plans, budgets, estimates, tender analysis, interim valuations, final accounts, loss-and-expense assessments and contract administration under JCT or NEC forms all shape what a project costs and who pays. When a number is wrong, the loss is measurable and often large.

That makes your exposure meaningfully different from a general building surveyor doing condition or valuation reports. A QS claim is rarely about a missed damp patch; it is about a cost overrun a client says you should have foreseen, an under-measured bill of quantities, an over-certified interim payment to a contractor who then became insolvent, or a defective final account. The alleged loss is the shortfall — and it can dwarf your fee.

Professional indemnity insurance responds to those civil claims: it covers your legal defence costs and any damages awarded, up to the policy limit, where a third party alleges you were negligent, breached your duty of care, or made an error or omission in your professional work. The mechanics of that placement are set out in our note on how a PI broker actually works.

Do quantity surveyors legally need PI insurance?

It depends on how your firm is regulated and what your contracts say.

• RICS-regulated firms — yes, it is mandatory. Any firm regulated by the Royal Institution of Chartered Surveyors (RICS) must hold PI cover that meets the RICS minimum terms. This is a condition of registration, not optional.
• Non-RICS firms — not a statutory requirement, but effectively unavoidable. There is no Act of Parliament forcing every cost consultant to carry PI. However, virtually every professional appointment, framework agreement and collateral warranty in UK construction requires it. Without cover, you will not win the work.

In practice, the question is rarely "must I?" but "at what limit, and for how long?". Even a sole-trader cost consultant advising on domestic extensions will find that lenders, main contractors and commercial clients insist on evidence of current PI before instructing them.

RICS minimum terms and cover limits

The RICS regime sets a floor, not a ceiling. For RICS-regulated firms the key features are:

• A minimum limit of indemnity tied to fee income. RICS scales the minimum limit to your firm's total fee income for the preceding year. Broadly, smaller firms must carry at least £250,000 or £500,000 each and every claim, and firms above the top fee-income threshold must carry at least £1,000,000 each and every claim. Check the current RICS Rules for the exact bands.
• "Each and every claim" basis. The limit must reinstate for each separate claim, rather than being a single annual aggregate that a first large claim could exhaust.
• Approved wording. The policy must meet the RICS minimum policy wording, including cover for negligence and a capped maximum uninsured excess.
• Run-off cover. When a firm closes, merges or stops trading, it must maintain run-off cover so that claims arising from past work are still met. RICS operates arrangements to support this.

PI is written on a claims-made basis: the policy that responds is the one in force when the claim is made against you, not the one in force when you did the work. That is why continuity of cover — and run-off after you stop — matters so much for a QS whose advice may not be tested until a dispute erupts years later.

Limits shown are generic illustrations only. Your required limit is set by RICS bands, your appointments and the value of the projects you advise on. Tell us about your work and we will size it with you.

The contractual side: appointments and collateral warranties

Even where RICS does not apply, your client documents usually will. Professional appointments frequently specify a required PI limit and a period for which you must maintain it — commonly six or twelve years after completion, reflecting the limitation period for contracts and deeds. Collateral warranties given to funders, purchasers and tenants often repeat that obligation.

Two traps for cost consultants:

• Aggregation of losses. RICS-compliant "each and every claim" cover protects you, but where a policy caps a class of losses in the aggregate, a single systemic error repeated across many valuations could erode one limit. Understand how your wording aggregates related claims.
• Uninsured obligations. If you sign an appointment promising a limit or a maintenance period your policy does not match, the gap is yours personally. Have the PI wording checked against the appointment before you sign, not after a claim.

What a QS PI policy typically covers

• Negligent cost advice — estimates, cost plans and budgets a client relied on.
• Measurement and quantification errors — under- or over-measured bills of quantities.
• Valuation and certification errors — over-certified interim payments, disputed final accounts.
• Contract administration failings — mishandled variations, extensions of time or loss-and-expense assessments.
• Defence costs — legal fees for defending a claim, which alone can be substantial.
• Breach of duty of care and negligent misstatement to clients and, where warranties exist, to third parties.

Exclusions and conditions vary by insurer and wording. Fraud, known circumstances not disclosed at renewal, and liabilities you assumed beyond your professional duty may fall outside cover — another reason to have appointments and wordings reviewed together.

How Apex places it

Apex Insurance Brokers is an FCA-authorised broker (FRN 724952) based in Bristol. For quantity surveyors and cost consultants we:

• Establish whether your firm is RICS-regulated and confirm the minimum limit and terms you must meet.
• Review your appointments and collateral warranties so the limit and maintenance period you buy match what you have contracted to hold.
• Approach insurers with genuine appetite for construction cost-advisory risk, rather than a generic professional package.
• Structure limits, excess and run-off so cover holds continuously — including when you cease trading or a project's liability tail outlives the work.

We explain the trade-offs in plain terms and place the risk with the insurer whose wording fits your practice. Start a quote and we will take it from there.

Common questions

Is PI insurance a legal requirement for a quantity surveyor?

Not by statute in itself, but if your firm is RICS-regulated it is mandatory under the RICS Rules. And whether or not RICS applies, your client appointments and collateral warranties will almost always require it, so in practice you cannot trade without it.

What limit of indemnity do I need?

At minimum, the RICS limit for your fee-income band (broadly £250,000 up to £1m each and every claim). In reality your appointments and the value of the projects you advise on usually push you higher — £2m or £5m is common on commercial and framework work.

Why do I still need run-off cover after I retire?

PI is claims-made, so a claim about work you did years ago is met by the policy in force when the claim is made — not when you did the work. Once you stop trading you have no live policy, so run-off cover keeps you protected for the remaining liability period.

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