How to Check a Contractor Licence in the UK (And What to Check Instead)

Anyone in the UK can print business cards, call themselves a general builder and quote for a two-storey extension by Friday. No exam, no register, no state licence. It is why so many homeowners end up with a half-built wall and a mobile number that no longer connects.

What we have instead is a patchwork: a few legally mandatory registrations covering the work that can kill you, plus voluntary schemes ranging from rigorous to a logo you can buy monthly. Checking properly takes forty minutes and costs almost nothing.

Only a handful of trades are restricted by law; everything else is unregulated, so the due diligence is yours. Get these wrong and the consequence is not a wonky worktop — it is carbon monoxide, an invalidated buildings policy and an unsellable house.

• •Gas — all gas work must be done by a Gas Safe registered engineer under the Gas Safety (Installation and Use) Regulations 1998. There is no DIY exemption, and signing off another's gas work is itself an offence.
• •Electrical — in England and Wales, notifiable Part P work (new circuits, consumer units, most bathroom work) needs a firm registered with NICEIC, NAPIT, ELECSA or STROMA, or advance notice to building control. Scotland and Northern Ireland differ.
• •Oil boilers need OFTEC, wood burners HETAS, replacement windows FENSA or CERTASS, and heat pumps or solar MCS plus TrustMark, which also gate Boiler Upgrade Scheme funding.
• •A builder carting rubble away needs Environment Agency waste carrier registration — fly-tipped waste traced back to your address is your Section 34 problem, not theirs.
• •Licensed asbestos removal needs an HSE licence.

Do not run these checks off a mobile number and a trading name. Ask for all of the below in one email and treat reluctance as your first result — a legitimate firm returns it within a day.

• •Registered company name and number, or the sole trader's full name, plus the registered office address.
• •VAT number if they charge VAT — free to validate on the HMRC checker.
• •Scheme numbers: Gas Safe licence, competent person membership, MCS or FENSA.
• •Insurance certificates as PDFs, showing policy number, insurer, expiry and limits of indemnity.
• •The name of whoever will actually carry out the notifiable work, which is rarely the person quoting.

Budget 30–45 minutes per contractor. Every mandatory register is free and answers in under a minute, as is Companies House. A commercial credit report on a limited company is £15–£40 and worth it before any five-figure deposit; a Land Registry title register is £3.

Call it under £50 all in, against an extension contract of £40,000–£80,000, or the £2,000–£6,000 routinely lost to a vanishing deposit. If you do not yet know what the job should cost, start with what a general contractor charges.

Work through these in sequence. The first four kill most bad actors before you have spent anything.

• •1. Separate the trading name from the legal entity: search the exact company number on the free Companies House register and confirm it matches the quotation.
• •2. Read the filing history, not the front page. Incorporation last month, overdue accounts, a proposal to strike off, or a director with three dissolved lookalike companies: phoenix trading is the best predictor of a lost deposit.
• •3. Search the mandatory register — Gas Safe by name, postcode or licence number; electricalcompetentperson.co.uk covers every Part P scheme at once; MCS, FENSA, OFTEC and HETAS have their own. It must be current today.
• •4. Check scope, not just presence. A Gas Safe ID card lists qualified categories on the back, and someone signed off for cookers is not qualified on your combi. Photograph both sides on the doorstep.
• •5. Verify insurance with the broker, quoting the policy number: £2m public liability (£5m for structural work), £5m employers' liability if they employ anyone — legally compulsory — and professional indemnity if they design.
• •6. Confirm who certifies. Notifiable work produces paper — a Gas Safe notification, an Electrical Installation Certificate, a building regs compliance certificate, a FENSA certificate. Agree that final payment follows the certificates.
• •7. Test the guarantee. Ten years from a firm that dissolves in year two is worth nothing, so ask who underwrites it.
• •8. Take references you choose — three clients from the last twelve months, then ring the second and third and ask what went wrong.

Most failures are ambiguous rather than damning, so put every query in writing.

If the replies get evasive, stop and re-tender — far cheaper than a dispute. Our list of contractor red flags covers the behaviour that usually accompanies a failed paper check.

• •Not on the register at all — for gas, electrical, oil or solid fuel that is unlawful, not merely unwise. Walk away.
• •Registered firm, unregistered individual — fine for a supervised apprentice, not for the person commissioning your boiler.
• •Registration lapsed last month — ask for the scheme's renewal confirmation before anyone starts.
• •A certificate the broker cannot confirm — edited insurance PDFs are a common scam. Treat it as forged.
• •Company incorporated three weeks ago — pay by card, cap the deposit at 10–25%, never prepay for materials.
• •'Cash, no certificate' — saves them tax, costs you the paperwork your solicitor will want at sale.

Tenants carry the safety risk but rarely do the hiring. The checks that matter most to you are free, take minutes and are completely reversible — you are reading documents, not touching the building.

Do not commission gas, electrical, structural or window work yourself: you become the client, you inherit the liability, and unauthorised alterations are the classic deposit deduction. Our rental-friendly decor guide sticks to changes that come off cleanly at check-out.

• •Ask for the paperwork you are entitled to: this year's Gas Safety Record (the CP12) and the EICR — fixed wiring must be inspected every five years and copied to you on request.
• •Check those numbers yourself. The Gas Safe licence number and the electrician's scheme number are printed on the certificates, and three minutes on the public registers confirms them.
• •Photograph the ID card of anyone working in your home.
• •Put repair requests in writing with dated photos — verbal reports do not exist at a deposit adjudication.
• •If the landlord will not act on a safety issue, contact the council's private sector housing team rather than arranging work yourself.

Paper checks confirm entitlement, not quality or price. Above roughly £30,000, or on anything structural, listed or party-wall related, £600–£1,500 for a RICS surveyor's specification and stage inspections routinely saves multiples of that.

Ring building control free before work starts if you are unsure whether the job is notifiable — our guide to when building regs and planning permission apply covers the grey areas.

Once a firm passes, the remaining risk is commercial rather than legal. Tighten it with the renovation contract checklist, then price the job using how to compare contractor estimates.