A subcontractor turns up on Monday morning with a certificate of insurance dated eighteen months ago. Is it still valid? Does it cover the work they are about to do? Are they actually the policyholder named on the certificate, or is it their old employer's policy from a previous job?
Verifying subcontractor insurance properly takes more than glancing at a certificate. This guide explains what UK law requires, what each type of insurance covers, and how to check the documents are genuine, current, and adequate for the work — without spending half your week on it.
You can also use our free employers' liability insurance expiry calculator to track expiry dates across your supply chain.
Why verification matters
If a subcontractor causes injury to one of their own workers, to one of yours, or to a member of the public — and they do not have valid insurance covering the work — the question of who pays does not go away. It comes back up the contractual chain. As the principal contractor (or main contractor), you can find yourself defending claims, settling losses, or facing regulatory action because a subcontractor's cover was not in force when it should have been.
This is also a regulatory question. The Employers' Liability (Compulsory Insurance) Act 1969 makes employers' liability insurance a legal requirement for any business with employees. The Health and Safety Executive can investigate and prosecute employers who operate without it. If a subcontractor on your site does not have it, your project is at risk too.
The three insurances a subcontractor typically needs
For construction subcontractors, three policies cover most of the risk:
1. Employers' liability insurance
What it covers: claims by the subcontractor's own employees for injury or illness arising from the work. Required by the Employers' Liability (Compulsory Insurance) Act 1969 for any business with at least one employee.
The minimum statutory cover is £5 million, although policies are commonly written at £10 million as standard in the construction sector. The Act and the Employers' Liability (Compulsory Insurance) Regulations 1998 set out the detail of how the cover must be provided, who must display the certificate, and the penalties for non-compliance.
Key exemptions: genuinely self-employed people with no employees are not legally required to hold EL insurance for themselves. But the moment they take on a labourer or apprentice, they need it. A subcontractor who tells you "I'm a sole trader, I don't need EL" may be technically right — or may have undeclared workers. This is one of the easier checks to get wrong.
2. Public liability insurance
What it covers: claims by third parties (members of the public, other contractors' workers, the client, neighbouring property owners) for injury or damage caused by the subcontractor's work.
Public liability is not a legal requirement under UK law — but it is almost universally required by construction contracts. The standard JCT and NEC contract forms require it, and most main contractors require it in subcontract terms. Typical levels are £2 million for low-risk trades, £5 million for general construction, and £10 million or higher for higher-risk work or larger projects.
3. Professional indemnity insurance
What it covers: claims arising from professional advice or design work. Required for any subcontractor providing design input — including design-and-build contractors and specialists who design temporary works or installation details.
Many trades that do not think of themselves as designers still carry design responsibility under modern construction contracts. M&E contractors, roofing specialists, and steelwork fabricators commonly do. If the subcontract package includes any design element, professional indemnity should be in place.
Other policies may apply to specific situations — contractors' all risks (CAR), contract works, hired-in plant — but employers' liability, public liability, and professional indemnity are the core three for verification purposes.
What to check on the certificate
A certificate of insurance is a document issued by the insurer (or their broker) summarising the cover in force. For each policy, verify the following:
- The insured. Is the named insured the subcontractor company you have engaged? Watch for parent / subsidiary / trading-name confusion — a certificate in the name of a holding company may not cover the trading subsidiary actually doing the work.
- The insurer. Is the insurer authorised to write the relevant business in the UK? FCA authorisation can be checked on the FCA Register.
- The policy number. A real policy has a number. Certificates without a policy number, or with vague reference codes, are a red flag.
- The period of insurance. When did the policy start, and when does it expire? Cover must be in force for the full duration of the subcontractor's work on your project. A policy expiring mid-job needs a renewal certificate before the gap.
- The limits of indemnity. Does the cover meet your contract requirement? £5 million is the minimum for employers' liability; the contract may require more. Public liability limits vary by project type.
- The business activities covered. Some policies exclude specific trades or activities — work at height, asbestos, hot works, demolition. If your subcontractor is doing any of these, check the policy covers them. The certificate may give a high-level description; in case of doubt, ask for the schedule of cover or the policy document.
- The territorial limit. UK construction projects are normally covered by policies issued for the UK, but watch for international subcontractors whose home-country policy may not extend to UK work.
How to confirm the certificate is genuine
A certificate is paperwork. Verifying it is genuine requires checking with the insurer or the broker named on it. The most reliable approach is to contact the broker directly using contact details obtained independently (their website, FCA Register) — not the contact details on the certificate, which can be falsified.
Ask the broker to confirm:
- The policy is in force as of today's date.
- The named insured is correct.
- The limits and period match the certificate.
- The policy has not been cancelled, suspended, or had material conditions imposed.
This is not paranoid — fake or expired certificates do circulate, particularly in lower tiers of subcontracting where the prequalification process is less rigorous. The cost of a five-minute broker call is trivial compared to the cost of discovering a fake certificate after an incident.
Worth knowing: under the Employers' Liability (Compulsory Insurance) Regulations 1998, an employer must display their current certificate of insurance — the Regulations require it to be accessible to every employee, which most employers operationalise by displaying it on a site office noticeboard or making it available electronically. The Employers' Liability Tracing Office (ELTO) was established by the insurance industry in 2011 and holds a database of employers' liability policies designed to help claimants trace historical cover. It is not a live verification tool for principal contractors — for that purpose, ask the broker.
How long to keep insurance records
For employers' liability specifically, the cover responds to claims for diseases (such as occupational asthma, hearing loss, or musculoskeletal disorders) that may emerge years after the exposure. The Department for Work and Pensions guidance and the ELTO scheme are built around the assumption that EL records may need to be referenced 40 years or more after the policy ends.
In practice for principal contractors:
- Keep a copy of the certificate in force at the time the subcontractor was working on each project.
- Keep evidence of the broker confirmation if you obtained one.
- Keep these records for the lifetime of the project plus the contractual limitation period (typically 12 years for a contract executed as a deed).
Digital records with searchable subcontractor and project metadata are easier to retrieve than paper folders. This is one of the strongest practical arguments for using subcontractor compliance software rather than spreadsheets.
What to do when a subcontractor cannot produce current insurance
The answer is not to let them on site anyway. If the subcontractor cannot produce a valid certificate before work starts, the contractual position is normally that they cannot start. From a regulatory perspective:
- If they should have employers' liability and do not, the work is illegal as well as uninsured.
- If they have a gap between policies (expired old policy, new policy not yet issued), they should bridge the gap with a broker letter confirming continuous cover. Without that, the gap is a real exposure.
- If they have employers' liability but it does not cover the specific work (excluded trade, excluded activity), they need a policy that does.
Removing a subcontractor mid-project for an insurance failure is expensive — replacement procurement, programme delay, contractual disputes. The way to avoid that is to verify before they start, not after.
Building this into your prequalification process
Insurance verification is one of the core elements of contractor prequalification, alongside accreditations, references, and method statements. Our contractor prequalification questionnaire guide covers the full structure; insurance specifically sits under section 4 of that guide.
For a more general view of how UK principal contractors verify subcontractor competence, see our HSE contractor management guide.
How software helps
The challenge with subcontractor insurance is rarely the first check — it is keeping up with policies as they renew, lapse, or change limits. Across a supply chain of 20-50 subcontractors, that means 60-150 policies all expiring on different dates, and manual tracking via spreadsheet falls apart.
Our free employers' liability insurance expiry calculator lets you record expiry dates and produces a traffic-light dashboard for your supply chain.
SubComply is being built to automate the full subcontractor compliance workflow — insurance, CSCS cards, RAMS, accreditations, all expiring on different dates, all tracked in one place with email alerts before each expiry. Join the waitlist to be notified when it launches.