How to vet a contractor before you sign anything

Home improvement is one of the most common sources of consumer complaints, largely because the sums are large, the work is hard for a homeowner to judge, and the money often changes hands before the work is done. The good news is that a careful homeowner can avoid most problems with checks that cost nothing but time. Work through them in order; each step makes the next one easier.

Find candidates the right way

The best leads come from people who have had similar work done recently and can show you the result: neighbours, friends, local community groups, and suppliers such as timber merchants or plumbing wholesalers, who see which trades pay their bills and come back for more work. Be cautious about anyone who approaches you first. Door-to-door offers (“we’re working down the road and have leftover materials”) and contractors who arrive after storms are a well-known pattern for poor work and advance-payment scams.

Aim for at least three written bids for any significant job. Beyond price, bids let you compare how each contractor understood the job. If one quote is far lower than the others, find out what it leaves out rather than assuming it is a bargain.

Check the licence, insurance and registration

In the US, licensing for contractors is handled by states and sometimes by cities or counties, and requirements vary widely by trade and job size. Most licensing bodies offer a free online lookup. Confirm that the licence is active, that it is in the name of the business you are dealing with, that it covers the type of work, and whether there are disciplinary actions or complaints on file. Then ask for proof of insurance — at minimum general liability, and workers’ compensation if they have employees — and verify it with the insurer directly. Our guide to checking licences and insurance covers this in detail.

In the UK, there is no single licence for builders, but some work is regulated: anyone working on gas appliances must be on the Gas Safe Register, and electrical work in homes is often done by electricians registered with a competent person scheme who can self-certify compliance with building regulations. TrustMark is a government-endorsed quality scheme for trades.

Talk to references and look at real work

Ask for two or three recent customers who had similar work done, and call them. Useful questions: Did the job finish on time and on budget? How were changes handled? Did the crew clean up? Were there problems afterwards, and how were they dealt with? Would you hire them again? If possible, look at a finished job in person. Separately, search the business name and owner’s name with “complaint” and check local consumer protection offices and review platforms.

Get a written contract with the right details

A proper contract protects both sides. Before signing, make sure it includes:

• The contractor’s legal name, address, and licence number.
• A detailed scope of work, including materials by brand or specification where it matters.
• Start and completion dates, and what happens if they slip.
• The total price and a payment schedule tied to completed stages.
• Who obtains permits and arranges inspections.
• How changes (“change orders”) are priced and approved in writing.
• Clean-up, waste removal and protection of your property.
• Any warranty on workmanship and how to claim.

Never sign a contract with blank spaces, and keep a copy of everything, including texts and emails about the job.

Keep payments behind progress

A reasonable deposit to secure a start date or order custom materials is normal. Paying most of the job upfront is not. Some states cap deposits by law: California, for example, limits the down payment on most home improvement contracts to 10% of the contract price or $1,000, whichever is less. Wherever you are, structure payments so that money follows completed work, and hold back a final payment until the job is finished, inspected and any snags are fixed.

In the US, subcontractors and suppliers who are not paid by your contractor can, in many states, place a mechanic’s lien on your property — even if you paid the contractor in full. Asking for lien waivers from the contractor and major suppliers as you pay reduces that risk.

Pay by a traceable method, ideally a credit card or cheque made out to the business name, never cash to an individual. See the safest ways to pay for why this matters.

Know your cooling-off rights

In the US, the FTC’s Cooling-Off Rule generally gives you three business days to cancel a sale of $25 or more made at your home, and the seller must tell you about this right. Some states add their own rules for home improvement. In the UK, contracts agreed in your home are typically “off-premises” contracts with a 14-day cancellation period, although you may have to pay for work you asked to start during that time. Check the specifics for your area before relying on them, and never let urgency (“this price is only good today”) override these checks.