How to verify a tradesperson before you hire in London

London's trade market is busy, fragmented and - for the unwary - still fertile ground for cowboys. The safest habit is simple: verify on official registers before you share a deposit. Logos, five-star screenshots and a confident van wrap are marketing. Gas Safe, NICEIC, TrustMark, WaterSafe and Companies House are checks you can do yourself in an afternoon.

This article is aimed at homeowners and small landlords hiring for domestic work in Greater London. Processes below are taken from scheme and consumer-advice sites as published; always re-check the live register on the day you appoint someone.

1. Match the register to the work

Gas. For boilers, cookers, fires and other gas work, UK law requires a Gas Safe registered engineer. The Health and Safety Executive's domestic gas FAQs state that anyone employed to work on gas appliances in domestic premises must be Gas Safe registered and competent in that area of work, with competencies marked on the engineer's ID card. Use the official Gas Safe Register find and check tools. HSE also publishes freefone and text-check guidance on its domestic gas FAQ page. A CSCS card is irrelevant to gas legality.

Electrics. For domestic electrical installation work in England and Wales, competent-person schemes such as NICEIC allow registered electricians to self-certify certain work. NICEIC warns that rogue traders have been known to misuse its logo, and recommends checking the business on NICEIC's own find tool (or contacting customer services if the trading name does not match). Do not accept a van sticker as proof.

Water and plumbing. For work affecting water fittings and supply quality, search WaterSafe. WaterSafe describes itself as a free industry-backed directory of approved plumbers and notes the value of Certificates of Compliance for homeowners.

Broader home improvements. Use TrustMark's find-a-tradesperson search for the specific trade you need. TrustMark is the Government Endorsed Quality Scheme; registered firms are vetted and monitored via Scheme Providers.

2. Companies House - useful, limited

If you are quoted by a limited company, search Companies House. Confirm the company is active and that the name and registered office roughly match the quote and letterhead. That check reduces the risk of dealing with a dissolved or misnamed entity. It does not tell you whether the directors are good builders, whether the firm is insured, or whether the person on site is Gas Safe registered.

3. The CSCS caveat every homeowner should know

Citizens Advice mentions CSCS cards as one example of proof of construction qualifications you can ask to see. That is fair - but incomplete if you stop there. The official CSCS FAQs explain that a card shows qualifications and training for the occupation shown (skills and knowledge), while employers must still assess experience and behaviours. CSCS also states that holding a card does not automatically grant site access, and that cards are not a legal requirement for everyone, though many principal contractors require them.

In plain English for a domestic hire: a green Labourer card does not prove someone is a qualified gas engineer, electrician or bathroom specialist. Always pair any CSCS evidence with the statutory register for regulated work.

4. Insurance, references and written scope

Citizens Advice's guide Before you get work done on your home recommends approved-trader and competent-person routes, checking memberships on the scheme website, asking for references, and being especially careful with doorstep or phone approaches. Ask to see insurance with matching business names and current dates. Get a written quote that lists labour, materials, exclusions, timescales and payment stages.

GOV.UK's note on recommendation sites adds another layer: prefer platforms that verify licences and insurance rather than relying only on self-reported claims, and compare several options rather than hiring the first name you see.

5. Deposits and payment discipline

TrustMark's homeowner guidance advises against choosing solely on the cheapest cash deal, and recommends paying for work done rather than large advances, while recognising a materials contribution may be asked when goods are bought. For London jobs:

• avoid paying the full contract sum before work starts;
• prefer staged payments tied to defined milestones;
• keep bank transfers and invoices - not unmarked cash;
• agree variations in writing before extra money changes hands.

6. Red flags

• Registration claim that cannot be found on the official Gas Safe, NICEIC, WaterSafe or TrustMark tools;
• Pressure to decide the same day after an unsolicited visit;
• Refusal to provide a business address or written quotation;
• Insurance document in a different trading name;
• Too busy for paperwork on a job that needs certificates;
• Treating a CSCS card as if it replaced Gas Safe or Part P registration.

7. When things go wrong

Raise a written complaint with the trader first. Scheme-registered firms often have Scheme Provider or ombudsman routes (TrustMark publishes a complaints process). For suspected illegal or unfair trading, Citizens Advice explains how to report to Trading Standards via its consumer service - noting that Trading Standards investigate and may take enforcement action, but will not usually recover your money for you.

Verification is not distrust; it is normal due diligence. The registers exist so Londoners can hire with evidence, not hope.

A one-hour verification routine you can repeat

Open three browser tabs: the statutory register for the work (Gas Safe, NICEIC, WaterSafe or TrustMark), Companies House if they are limited, and your email draft requesting insurance and a written scope. In sixty minutes you can usually confirm whether the trading name matches the register, whether the company is active, and whether the person quoting will put programme and price on letterhead. Save PDFs or screenshots with the date visible.

When the engineer or electrician arrives, check the photo ID and licence number again against the register before they open the boiler case or consumer unit. HSE's gas guidance specifically encourages consumers to verify the engineer who attends, not only the business that took the booking. The same discipline helps for electrical and water work: the badge on the van is not the person holding the tools.

If a recommendation comes from a neighbour, still run the registers. Honest tradespeople expect it. The ones who object to being checked are selecting themselves out of your shortlist - which is exactly what you want.

What good paperwork looks like before day one

A trustworthy tradesperson will usually be willing to email a quotation that states the business name, address, scope of works, exclusions, approximate dates, payment stages and any certificates they will issue. You should be able to reconcile that document with the register listing and, for limited companies, with Companies House. If the email address is a free webmail account with no matching letterhead, ask for stronger identity evidence before you pay a deposit.

For multi-trade jobs - for example a kitchen that needs gas, electrics and plumbing - insist on knowing which registered person is responsible for each regulated element. A single project manager is fine; anonymous subcontractors doing gas work are not.

Sources checked 15 October 2026: HSE domestic gas FAQs; Gas Safe Register; NICEIC: how to check registration; CSCS FAQs; TrustMark; Citizens Advice; GOV.UK recommendation-site advice. General information only.