Red Flags in Builder Quotes

If one quote is dramatically cheaper than three or four others, something is missing. Either the builder has underestimated the work, is planning to cut corners on materials, or intends to hit you with 'extras' once work is underway.

A professional quote breaks down labour, materials, and other costs line by line. A single total with no breakdown makes it impossible to compare quotes fairly or challenge unexpected charges later.

A quote that reads £5,000 for plastering, £10,000 for brickwork, £3,000 for electrics has almost certainly been guessed rather than calculated. Real costs have odd numbers because they're based on actual measurements and material prices.

A deposit of 10–15% is reasonable for ordering materials. Anything above 25% before work starts is a major red flag — legitimate builders don't need your money to fund other jobs. Stage payments tied to milestones are the industry standard.

Paying cash isn't illegal, but a builder who insists on cash and won't provide a VAT receipt may be evading tax — and you'll have no paper trail if things go wrong. Always get a receipt.

Material prices change. A quote without a validity period (typically 30–60 days) means the builder can change the price at any time before you accept, leaving you with no certainty.

If a builder says 'don't worry, we'll sort it out' but won't confirm details via email or a written quote, they're leaving themselves room to change the story later. Everything should be documented.

'This price is only good if you sign today' is a classic high-pressure sales tactic. A genuine builder won't mind if you take a few days to compare quotes and think it over. Urgency is manufactured to stop you doing due diligence.

If they can't give you a rough start date and duration, they're either overcommitted on other jobs or haven't properly thought through your project. Either way, you'll be waiting longer than you expect.

Every decent builder has happy customers who'd vouch for them. If they can't name a single reference or let you see past work, ask yourself why. New businesses can still show photos and offer contact details for recent clients.

If it takes a week to get a reply to a simple question before they've started, expect worse once they have your deposit. Consistent communication is a hallmark of professionalism.

A handshake agreement might feel friendly, but it leaves you with no legal protection if the builder walks off the job, demands more money, or delivers substandard work. Insist on a written contract — always.

What happens if you need to cancel? What if the builder can't continue? A contract without cancellation terms leaves both sides exposed. Look for reasonable notice periods and clear terms on any refund of deposits.

A defects period (typically 6–12 months) means the builder will return to fix any problems that emerge after completion. Without one, getting snags fixed becomes a favour rather than an obligation.

Read the scope of works carefully. Builders sometimes exclude items you'd naturally assume are included — decoration after plastering, waste removal, building control fees, or connecting services. If it's not in the contract, it's not in the price.

If you want to change something mid-project (and most people do), the contract should explain how variations are priced, agreed, and documented. Without this, you'll end up in a he-said-she-said dispute about costs.

Public liability insurance covers damage to your property and injuries to third parties. Ask for a copy of the certificate — you want at least £2m cover for domestic work. Don't accept 'I'm covered' without seeing proof.

Membership of the Federation of Master Builders (FMB), TrustMark, Checkatrade, or similar bodies isn't mandatory, but it shows a commitment to standards and gives you a complaints route. Builders who are members tend to take their reputation seriously.

If they have no photos, no website, no Google reviews, and no Checkatrade profile, how do you know what you're getting? Even sole traders building a reputation will have a phone full of project photos.

Check Companies House for limited companies, or ask for a trading address. A builder who only has a mobile number and no traceable business presence is much harder to pursue if something goes wrong.

Gas Safe registration, NICEIC certification, FENSA registration — if the work involves gas, electrics, or windows, the builder (or their subcontractors) must hold the right certifications. Ask to see them before work starts.

Each phase of work should be listed separately with clear costs. This lets you compare quotes meaningfully and understand exactly where your money is going.

A good scope reads like a step-by-step description of the project. It should be specific enough that another builder could read it and know exactly what work is covered.

An honest builder will list what's NOT included — decoration, landscaping, building control fees, or anything else you might assume is part of the job. This transparency prevents disputes.

Stage payments based on work completed (foundations, first fix, second fix, completion) align the builder's incentives with progress. You pay for what's done, not what's promised.

The quote or accompanying terms should state how long the builder guarantees the work, what's covered, and how to report defects. Twelve months is standard; some offer longer through insurance-backed guarantees.

Material costs and availability change. A validity period gives you time to compare and decide while ensuring the builder can honour the price if you accept within the window.

Multiple quotes give you a realistic range for your project. If one is dramatically different (high or low), that outlier deserves closer scrutiny.

Don't rely on the references the builder provides — they'll obviously pick their happiest clients. Search Google reviews, Checkatrade, and social media for a fuller picture.

Call the insurer to check the policy is active. Check Gas Safe, NICEIC, or FENSA registrations online. Companies House and the FMB website let you verify membership claims.

Upload your quote to MyBuildAlly for an independent assessment. Our AI analyses pricing, scope, and identifies gaps — giving you the confidence to negotiate from a position of knowledge.

If something feels off, it probably is. A builder who makes you uncomfortable before the work starts won't improve once they have your money. It's always better to wait for the right builder than rush into a bad decision.