How to Manage Subcontractors in Construction: A Compliance-First Approach

You've won the contract, appointed your subcontractors, and work starts next week. But before a single operative steps on site, you need to know: are they actually compliant?

Managing subcontractors in construction isn't just about scheduling trades and chasing progress. Under CDM 2015, principal contractors have a legal duty to verify every subcontractor's competence, insurance, and documentation before they begin work. Get this wrong, and you're exposed — legally, financially, and operationally.

This guide walks through a compliance-first process for managing subcontractors on UK construction projects, from pre-qualification through to ongoing monitoring. For the full regulatory breakdown, see our CDM compliance guide. For a plain-English overview of what CDM compliance means and what the penalties are, see What is CDM compliance?.

Step 1: Pre-qualify before you appoint

Before signing a subcontract, verify that the firm can actually meet your compliance requirements. This isn't a tick-box exercise — it's your first line of defence under CDM Regulation 8, which requires you to ensure anyone you appoint has the right skills, knowledge, experience, and organisational capability.

Minimum pre-qualification checks:

• Employers' liability insurance — minimum £5M cover, current certificate with expiry date noted. This is a statutory requirement under the Employers' Liability (Compulsory Insurance) Act 1969. Fine for non-compliance: up to £2,500 per day.
• Public liability insurance — cover level matching your contract requirements (typically £1M–£10M depending on project value).
• CSCS cards for all operatives who will work on site. Check that the card type matches the work they'll do — a labourer card doesn't cover skilled trade work.
• CIS registration — verify the subcontractor's tax status with HMRC. You need to apply the correct deduction rate (0%, 20%, or 30%) from the first payment.
• Health and safety policy — a legal requirement for any business with five or more employees.
• Trade-specific certifications — Gas Safe registration, NICEIC, IPAF, PASMA, or other accreditations relevant to the work scope.
• References or track record — evidence they've delivered similar work safely and to standard.

Record the results of your pre-qualification checks. If a subcontractor can't provide the basics before appointment, that's a clear signal. Our free PQQ template covers all of these areas in a structured, downloadable format.

Step 2: Collect documentation before site access

Once appointed, collect the full compliance pack before the subcontractor starts on site. Not during the first week. Not "when they get around to it." Before they start.

The compliance pack should include:

• Current insurance certificates (EL, PL, PI if applicable)
• CSCS card details for every operative
• CIS verification confirmation
• Risk assessments and method statements (RAMS) specific to the work they'll do on your project
• Evidence of relevant training and competence
• Signed agreement to your site rules and safety standards

The common failure here is accepting generic RAMS. If the subcontractor hands you a template risk assessment with another project's name scratched out, send it back. RAMS must be site-specific and cover the actual hazards the operatives will face on your project.

Step 3: Induct every operative

CDM 2015 requires principal contractors to ensure all workers receive a site-specific induction before starting work (Regulation 14). This induction should cover:

• Site-specific hazards and risks
• Emergency procedures (assembly points, first aid, fire)
• Site rules (PPE, access restrictions, welfare facilities)
• Reporting procedures for near-misses and hazards
• Key contacts (site manager, first aider, fire marshal)

Record who was inducted, when, and by whom. Keep these records accessible — an HSE inspector or client auditor may ask to see them.

Step 4: Monitor compliance throughout the project

This is where most contractors fall down. Pre-qualification and induction happen at the start. But compliance isn't static — documents expire, personnel change, and work scopes evolve.

Ongoing monitoring should include:

• Insurance expiry tracking — set reminders at 30, 14, and 7 days before certificates expire. Chase renewals before cover lapses, not after.
• CSCS card checks — verify cards are still valid, especially for long-running projects. Cards expire, and new operatives may join mid-project without being checked.
• CIS re-verification — subcontractor tax status can change between tax years. Re-verify periodically to ensure correct deduction rates.
• RAMS reviews — if the work scope changes, the risk assessment must be updated. A RAMS written for groundworks doesn't cover the roofing phase.
• Site inspections — regular walkdowns to verify that the work matches the method statement and that PPE and safety controls are being followed.

The practical challenge is scale. With 20 or 30 active subcontractors, each with multiple documents and expiry dates, manual tracking in spreadsheets becomes unreliable. By the time someone notices a gap, it may have existed for weeks. Our free insurance expiry calculator can give you an instant snapshot of which subcontractors have expiring or expired cover.

Step 5: Handle non-compliance promptly

When you identify a compliance gap — and you will — act immediately. Typical scenarios:

• Expired insurance: Stop the subcontractor's work until a current certificate is provided. An employer operating without valid EL insurance commits a criminal offence under the EL Act. Separately, allowing uninsured subcontractors on site undermines the competence evidence you need under CDM Regulation 8.
• Missing CSCS cards: Operatives without valid CSCS cards should not be on site. While CSCS is not a direct statutory requirement, most clients require it and it serves as key evidence of competence under CDM Regulation 8.
• Outdated RAMS: If the risk assessment doesn't cover the current work, issue a stop until it's updated and reviewed.
• Unsafe practices observed: Address immediately, record the intervention, and follow up with the subcontractor's management.

Document everything. A clear audit trail of compliance checks, identified issues, and corrective actions demonstrates you've taken "reasonably practicable" steps — which is the legal standard under UK health and safety law.

The compliance-first mindset

Most subcontractor management guidance starts with contracts and scheduling. Compliance is treated as an afterthought — something to sort out in parallel or "when the paperwork catches up."

That approach creates risk. A compliance-first process means:

1. No appointment without pre-qualification
2. No site access without a complete compliance pack
3. No work without site-specific induction
4. No complacency — monitor throughout, not just at the start
5. No tolerance for gaps — act on non-compliance the day you find it

This isn't about being difficult. It's about protecting your workers, your subcontractors' workers, your business, and your licence to operate. Principal contractors who manage compliance proactively spend less time scrambling during audits and more time building.

Sources

• The Construction (Design and Management) Regulations 2015 (SI 2015/51)
• HSE — Principal contractor duties under CDM 2015
• Employers' Liability (Compulsory Insurance) Act 1969
• GOV.UK — Construction Industry Scheme

This guide is for informational purposes and does not constitute legal advice. For project-specific compliance questions, consult a qualified health and safety professional.

Last reviewed: 11 March 2026