How to Check a Builder Is Legit

No licence or statutory register exists for builders in the UK. What the law regulates is the work. Most building projects need building regulations approval, which is separate from planning permission, and you may need both.

Approval comes one of two ways. You or your builder apply to the council's building control, or a registered building control approver, who inspects as the work goes up and issues a completion certificate at the end. Or, for work covered by a competent person scheme, the installer self-certifies and the certificate is issued for you. A loft conversion always needs approval: floor strength, roof stability, fire escape, stairs and sound insulation are all checked. So do extensions and most structural changes.

A builder who cannot tell you which route your job will take, or who suggests skipping building control to save money, has told you what you need to know. Without the certificates you will struggle to sell the house.

• Federation of Master Builders. FMB checks a firm's trading history, credit history and directors, asks for proof of public liability insurance, then sends an independent inspector to a current or recent client's site before admitting them. Search at fmb.org.uk/find-a-builder and confirm a specific firm through the check-a-member page on the same site. FMB members must give written quotes and contracts and pass on guarantees and certificates, and FMB runs a free dispute resolution service for members' clients.
• TrustMark. The government-endorsed quality scheme. Registered businesses must carry a minimum two-year guarantee on workmanship and products, insured against the business failing, and unresolved complaints go to the Dispute Resolution Ombudsman. Search at trustmark.org.uk/homeowner and check the firm is registered for building work specifically.
• Buy With Confidence. Run only by local authority Trading Standards services; every listed business has been vetted by Trading Standards. Search at buywithconfidence.gov.uk. Citizens Advice's own first step is your local council's approved trader list.

Check on the scheme's own website every time. A logo on a van, a website or a quote proves nothing.

Companies House. If the builder is a limited company, search the name at find-and-update.company-information.service.gov.uk. Read the incorporation date, the current and former directors, the filing history, any charges and any insolvency notes. A director whose previous building companies were dissolved is a fact worth having. Companies House does not check what is filed, so a clean record is the start of the checking, not the end. A sole trader will not appear; sole traders register only with HMRC.

VAT. If the quote charges VAT, ask for the VAT number and check it at gov.uk/check-uk-vat-number. The check returns the name and address the number belongs to.

Public liability insurance. Ask for the certificate, check the insured name matches the firm quoting you, and check the policy runs to the end of the job. If they have none, damage to your home is your problem.

Employers' liability insurance. Any builder with employees must hold it by law, with at least £5 million of cover, and must display the certificate. A firm that turns up with a crew and cannot show one is breaking the law before starting your job.

Three separate permissions can apply to one job, and a good builder knows which.

• Planning permission is about what you build and how it looks. Building something new, a major change such as an extension, or a change of use usually needs it. Many extensions and loft conversions fall within permitted development if they stay inside the size limits. Ask the council's planning department, not the builder.
• Building regulations approval is about how it is built: structure, fire, insulation, drainage, electrics. Needed for almost all extensions, conversions and structural work.
• The Party Wall Act 1996 applies in England and Wales when you work on a shared wall, build a new wall at the boundary, or excavate within three or six metres of a neighbour's building. You must serve notice, two months ahead for work on an existing party wall and one month for the rest. The neighbour has 14 days to reply; silence counts as a dispute, resolved by a surveyor's award.

Get three written quotes, fixed prices rather than estimates, each showing VAT if the firm is VAT registered. Then put the job in a written contract: start and finish dates, what is included, who supplies materials, what happens if the work runs late, and when each payment is due.

You do not have to draft it. The Joint Contracts Tribunal publishes a Building Contract for a Home Owner/Occupier, written for extensions and alterations, covering price, payment, working period, insurance, disputes and cancellation. A builder who has never heard of it is unusual; one who refuses to sign any contract is a decision made for you.

On money, Citizens Advice is specific: no more than 25 per cent as a deposit, payments in stages as work is completed, and card payments where possible so Section 75 or chargeback protection applies. For a large deposit, ask about deposit protection insurance or an escrow account regulated by the FCA.

• Cold calling, at the door or by phone.
• No written quote, so the price goes up and up.
• Urgent faults "found" once work starts, with repeat demands for more money. Hackney Trading Standards reported a case where several thousand pounds went upfront and more than £20,000 was then demanded for extras.
• Cash only, or a price far below every other quote.
• A mobile number and a first name, no business address.
• Refusing references, or references you cannot phone.

If a contract was agreed at your home you have 14 days to cancel, unless you invited the builder in for urgent repairs. If work has already gone wrong, the Consumer Rights Act 2015 requires reasonable care and skill: write to the builder with the fault and a deadline, use the FMB or TrustMark dispute route if they belong to one, then the Citizens Advice consumer helpline on 0808 223 1133 and, for money owed, a county court money claim. A letter before action comes first, and mediation is often quicker than court.