Contractor onboarding checklist 2026: get a new subcontractor site-ready properly

Onboarding a new contractor or subcontractor is the moment where compliance problems are either caught or quietly created. Do it properly and you know, before they set foot on site, that they are insured, competent and fit for the work. Do it by email and you end up chasing PDFs for a fortnight and approving on trust because the job has to start. This checklist walks through a clean onboarding from first contact to approved, explains why each step matters, and shows how to strip out the friction that makes the whole thing drag.

Step 1 — Decide what this job actually needs

Before you request a single document, define the requirements for this specific job: the trade and scope, the minimum insurance cover level, which accreditations the client or contract demands, and the qualifications the work requires. This step is skipped more than any other, and it is the one that makes everything downstream work. A generic request — "send us your insurance and RAMS" — produces generic documents you cannot really assess. A specific request — "public liability at five million, a RAMS for this scope, CSCS cards for the operatives attending" — gets you exactly what you can approve against, and signals to the contractor that you actually check.

Step 2 — Request the documents

With the requirements set, request what the job needs:

• Public and employers' liability insurance certificates, at the levels you specified.
• A job-specific RAMS, and a COSHH assessment where substances are involved.
• Accreditations — CHAS, SMAS, SafeContractor or Constructionline as required.
• Trade qualifications and cards for the people who will actually be on site.
• Right-to-work confirmation, and references for significant or higher-risk work.

Ask for everything at once, clearly, rather than discovering gaps one at a time — the drip-feed of "and can you also send..." is what turns onboarding into a fortnight of email.

Step 3 — Verify, do not just collect

This is the step that separates real onboarding from a folder of PDFs. Check each document against the requirements from step one: is the RAMS genuinely for this trade and scope, does the insurance meet your minimum and cover the actual work, are the certificates and cards in date for the job dates, are the cards held by the people attending? A document that exists is not the same as a document that fits, and under the pressure to get started it is dangerously easy to treat "received" as "approved". This is precisely the work that contractor onboarding software does for you, returning a verdict per document rather than leaving you to read the small print on a Friday afternoon.

Step 4 — Approve and record

Once everything checks out, approve the contractor and keep the record: who approved them, when, and against what requirements. That record is not bureaucracy — it is what you produce for a client pre-start check or a CDM audit later, and it is what protects you if a question arises about whether a contractor should have been on site. An approval nobody can evidence is only half an approval.

Step 5 — Set the renewals

Onboarding is the first gate, not the finish line. The insurance you just verified will expire; the accreditation will lapse; cards will run out. Make sure every renewal date is tracked from day one so the contractor stays compliant for the whole time they work with you, not just on the day you took them on. This is where a spreadsheet-based onboarding quietly fails weeks later — the checks were done once and never repeated — and where ongoing contractor compliance software earns its place.

Remove the friction

The reason onboarding stalls is almost always friction. Asking a busy subcontractor to create an account and a password to send you a certificate loses a fraction of them at every step. Chasing missing documents by email costs your side hours. Reading certificates by eye is slow and error-prone. Strip all three out — request the exact documents once, let the contractor upload from a single secure link with no account, and have each document checked automatically — and onboarding stops being the bottleneck it usually is. A process that is easy for the contractor is a process that actually gets completed.

For principal contractors and property managers

If you onboard subcontractors repeatedly, the value of doing this consistently compounds. Fold the checklist into a standard onboarding flow so it happens the same way every time, before work starts, and keep the evidence for CDM and client requirements. Subcontractor management software builds the whole supply chain around exactly this flow, site by site; property managers use the identical process for the trades they instruct across a portfolio. The steps do not change — only the setting does.