How to check a builder before you hire (free official registers)
The short answer: ten minutes on free official registers before you sign saves months of dispute. Check the company exists, check the tradesperson is registered for the regulated work (gas, electrics, glazing), and check what their membership actually certifies. No single register "approves" all builders — here is what each one really tells you.
REVIEWED BY: Sean McNamara on 2026-09-03
The free checks, in order
1. Companies House — find the company. Does it exist? How old is it (a company registered three weeks ago is not automatically bad, but it changes your risk)? Who are the directors — and have they been directors of other construction companies that were dissolved with debts? The filing history shows it. 2. TrustMark — the government-endorsed quality scheme (verified 2026-09-03). Search for the firm and trade; membership means vetting and a complaints procedure — it is not an unlimited guarantee. 3. Federation of Master Builders — Find a Builder (verified 2026-09-03). FMB members are independently vetted and can offer insurance-backed warranties on their work. 4. Gas Safe Register — Check An Engineer (verified 2026-09-03). Gas work by an unregistered engineer is illegal. Check the engineer's licence card number, not just the company. 5. FENSA / CERTASS (glazing) — replacement windows and doors need certification; check the installer and order your certificate via FENSA (verified 2026-09-03). 6. Electrical competence — for notifiable electrical work, look for NICEIC or NAPIT registration (many are also findable via TrustMark). 7. HMCTS Find a Court — not for vetting builders, but know your venue before you ever need it: find-court-tribunal.service.gov.uk (verified 2026-09-03).
What a membership does NOT mean
- It is not insurance. Insurance-backed warranties are separate products — ask for the policy documents in writing.
- It is not a guarantee of this specific job. Schemes vet firms at a point in time; your contract is what binds them to your job.
- It is not the only good-builder filter. Excellent small firms exist outside every scheme — that's why the contract, payment structure and written scope matter more than logos.
The paper that protects you more than any logo
1. A written quote, itemised — scope, materials, start, duration, price, payment stages. See quote vs estimate. 2. Staged payments tied to completed work — never large sums up front; hold a retention (5–10%) until snagging is done. 3. Variations in writing — "as discussed" is where disputes are born. 4. A contract note even for small jobs — an email exchange confirming the above is a contract in substance.
If you're reading this after hiring
The registers still help: they tell you whether the work that was done was legally compliant (gas certificates, FENSA certs) — and a missing certificate is itself evidence. Then move to the evidence guide and your rights under the Consumer Rights Act 2015.
Sources: official registers as linked above, each verified 2026-09-03. This page is general information, not legal advice. Listing a register does not endorse any firm; listings on this site are never paid placements.
Preparing a claim? EvidenceCanvas (Casewright) helps you organise your evidence and draft pre-action documents for the small claims track. It is not a law firm and does not give legal advice.
Reviewed by Sean McNamara · 2026-09-03 · Independent information directory — not legal advice.