Subcontractor Vetting Compliance Checklist for UK Construction

Why Vetting Matters More Than You Think

Under CDM 2015, if you appoint a contractor or subcontractor, you have a duty to take reasonable steps to satisfy yourself that they're competent and adequately resourced to carry out the work safely. For a full breakdown of the contractor prequalification process, including how to structure your approach for different project sizes, see our dedicated guide. If a subcontractor causes an incident on your site and you can't demonstrate that you vetted them properly, the HSE will be asking you questions — not just them.

The consequences are real. HSE fines for duty-holder failures under CDM 2015 routinely reach five and six figures. But beyond the fines, there's the reputational damage, project delays, and the very real risk to workers' lives.

Yet many construction businesses still vet subcontractors informally. A quick phone call, a glance at a CHAS certificate, and a handshake. That's not due diligence — it's hope.

Insurance Verification

This is non-negotiable. Every subcontractor working on your site needs valid insurance, and you need to verify it — not just take their word for it.

Employer's Liability Insurance

• Minimum cover: £10 million (this is a legal requirement for any business with employees)
• Check: Certificate is current, covers the period of the contract, and the policyholder name matches the contracting entity
• Watch for: Sole traders who claim they don't need EL because they have no employees. If they use any labour — even casual or agency workers — they may need it

Public Liability Insurance

• Minimum cover: £5 million for most commercial work (some clients require £10 million)
• Check: Certificate is current, cover level meets your contract requirements
• Watch for: Policies with exclusions for specific activities (working at height, hot works, asbestos) that are relevant to the work they'll be doing

Professional Indemnity Insurance

• Required for: Design work, consultancy, surveying, or any role where professional advice is given
• Minimum cover: Typically £1 million, but varies by contract value
• Check: The policy covers the specific services being provided

Tip: Don't accept insurance broker confirmation letters as a substitute for the actual certificate. The certificate shows the exact cover, exclusions, and dates. A broker letter is a summary that may omit critical details.

Accreditations and Certifications

SSIP Membership

At minimum, subcontractors working on commercial construction projects should hold a current SSIP-recognised accreditation — CHAS, SafeContractor, or equivalent. This demonstrates that their health and safety management has been independently assessed.

• Check: Certificate is current (not expired or lapsed)
• Check: The accreditation scope covers the type of work they'll be doing
• Watch for: Companies showing accreditation in one entity name while contracting through another

Constructionline

For public sector work or larger commercial contracts, Constructionline registration is often required. Check their level (Standard, Silver, or Gold) matches the contract requirements.

Trade-Specific Accreditations

Depending on the trade, you should verify:

• Gas Safe Registration — mandatory for any gas work
• NICEIC/NAPIT — for electrical work under Part P
• FIRAS — for fire protection installation
• CISRS — for scaffolding operatives
• F-Gas Certification — for HVAC work involving refrigerants

Health and Safety Documentation

Health and Safety Policy

Every business with five or more employees must have a written H&S policy. Even for smaller subcontractors, a documented policy is a strong indicator of safety awareness.

• Check: Policy is signed, dated, and reviewed within the last 12 months
• Check: Named responsible persons are still employed by the company
• Check: The policy covers arrangements relevant to their trade

Risk Assessments and Method Statements (RAMS)

RAMS should be specific to the work they'll be doing on your project, not generic templates.

• Check: Risk assessments reference the specific hazards of your site and their activities
• Check: Method statements describe the actual sequence of work, not a generic process
• Watch for: Identical RAMS submitted for every project — this means they're using templates without tailoring them

COSHH Assessments

If the subcontractor will be using hazardous substances (adhesives, solvents, dust-generating processes), they should have COSHH assessments for each substance.

Ready to standardise your vetting process? Generate a free vetting checklist tailored to your framework and trade requirements.

Training and Competency

CSCS Cards

In 2026, there's no legitimate reason for a construction operative not to hold a valid CSCS card. Check:

• Card is valid (not expired)
• Card type matches the role — a labourer's card isn't appropriate for a skilled trade
• The card belongs to the person — photo ID on the card should match the individual

You should also verify that operatives have the correct PPE for their role on site — CSCS cards confirm competence, but PPE compliance is a separate check that's just as important.

Management Training

• SMSTS — for site managers (5-day course, valid for 5 years)
• SSSTS — for site supervisors (2-day course, valid for 5 years)
• Check: Certificates are current and the named individuals will actually be managing/supervising on your site

Trade Qualifications

• NVQs, City & Guilds, or equivalent for their specific trade
• Specialist training where relevant: working at height, confined spaces, asbestos awareness, temporary works coordination

First Aid

If the subcontractor is managing their own team on site, they should have at least one qualified first aider. Check the first aid at work certificate is current (valid for 3 years).

Financial and Legal Checks

Company Registration

Verify on Companies House that the company is active and not dissolved. Check the registered name matches the contracting entity and that there are no adverse filings.

CIS Registration

Verify their Construction Industry Scheme status. This protects you from liability for unpaid tax deductions.

References

Request at least two references from similar projects completed in the last 12 months. Actually call the referees — a written reference is easy to fabricate. Ask specifically about safety performance, quality of work, and reliability.

When to Re-Vet

Vetting isn't a one-time activity. You need to re-check subcontractors:

• Annually — for subcontractors on approved lists or framework agreements
• At contract renewal — when extending or renewing a subcontract
• After an incident — if a subcontractor is involved in a safety incident, re-verify their documentation
• When documents expire — insurance and accreditations have fixed expiry dates

The most common failure is the first-year vetting trap: you check everything thoroughly before the first contract, then assume it stays current. It doesn't. Insurance policies lapse. CSCS cards expire. Accreditations aren't renewed.

Red Flags to Watch For

Beyond the checklist, watch for these warning signs:

• Reluctance to provide documentation — a competent subcontractor has their compliance pack ready
• Documents with inconsistent company names — insurance in one name, accreditations in another
• Expired documents with verbal assurances — "the renewal is in the post" is not a valid certificate
• No CSCS cards — no legitimate reason in 2026
• Identical RAMS for every project — they're not being tailored to the specific work

Record Keeping

Keep a record of every vetting check. If the HSE investigates, they'll want evidence that you verified competence before work started.

Your records should include:

• Date of vetting check
• Documents reviewed (with copies or reference numbers)
• Expiry dates noted
• Who performed the check
• Outcome (approved, conditionally approved, rejected)
• Any conditions or follow-up actions

With ComplianceVault, subcontractor records sit alongside your own compliance documents — giving you a single view of who's been vetted and when their documents expire.

Summary

• Vetting subcontractors is your duty under CDM 2015 — if they're not compliant, you carry the risk
• Apply the same checklist consistently — insurance, accreditations, H&S documentation, training, and financial checks for every subcontractor regardless of size
• Re-vet annually and when documents expire — first-year vetting alone is not enough
• Keep records of every check — the HSE will ask for evidence that you verified competence before allowing work to start