Building trades in the UK are unlicensed, so checking a builder is down to you. The Federation of Master Builders advises asking for proof of active public liability insurance, comparing at least three itemised written quotes like for like, and agreeing a written contract before any work begins. These twelve questions cover the ground, and a good builder will answer every one of them clearly and in writing.
Experience and past work (questions 1–2)
1. Have you done recent projects like mine, and can I see them? Ask for examples of similar size and budget, when they were finished and what problems came up. 2. Can I speak to previous customers? Ask for two or three recent references with contact details and actually phone them — Citizens Advice notes that written references aren't always genuine, and advises avoiding traders who won't give any.
Insurance and credentials (questions 3–4)
3. Can I see your insurance certificates? Ask what cover they hold, such as public liability, employers' liability if they have staff, and contractors' all-risk, and check the dates run past the end of your project. 4. Which trade bodies or schemes are you registered with? Look each one up on the organisation's own register rather than trusting a logo. Gas work needs a Gas Safe registered engineer, and electrical work should be done by a registered electrician.
The quote (questions 5–6)
5. Is this a fixed price, and exactly what does it include? Citizens Advice says a quote is a fixed price while an estimate is only a guess; ask for a breakdown of the work and materials, whether VAT is included, and how long the price is valid. 6. What could make the price go up? Ask about any provisional sums, and agree in writing how changes will be priced and approved before extra work starts.
The contract and payments (questions 7–8)
7. Will you give me a written contract? It should cover what's being done, start and finish dates, materials, tidying up, subcontractors and payment; Citizens Advice says to be wary of anyone who won't put anything in writing. 8. How and when do you want to be paid? Aim to pay by card, in stages tied to finished work, and avoid large deposits — the FMB says around 10% is often used as a guide, and Citizens Advice says not to agree to more than 25%.
The team and the timetable (questions 9–10)
9. Who will manage the job, and who will be on site? Find out whether it's the builder's own team or subcontractors, and who to call when something goes wrong. 10. When can you start, and how long will it take? Get start and finish dates in writing, and ask what happens if the work is delayed.
Permissions and problems (questions 11–12)
11. Who is responsible for planning, building regulations and party wall notices? Some builders manage these and others expect you to, so agree it upfront and check the sign-off certificate is issued at the end. 12. How will snagging, defects and disagreements be handled, and what guarantee do you offer? The FMB recommends the contract covers insurance, warranties and guarantees, how defects and snagging are dealt with, and how disagreements are resolved.
Frequently Asked Questions
How many quotes should I get?
At least three written, itemised quotes based on the same description of the work, so you can compare them like for like rather than just comparing headline prices.
What deposit is reasonable for a builder to ask for?
A small deposit is common on larger projects, particularly for materials or made-to-order items. The FMB says around 10% is often used as a guide, and Citizens Advice says not to agree to more than 25%. Ask what it covers, get it in the contract, and get a receipt.
Should I be worried if a builder only gives me a mobile number?
Citizens Advice says to be wary, because the trader may be hard to contact if problems come up. Do all the other checks — insurance, references, registers — before deciding.
Where this information comes from
- Federation of Master Builders — How to choose a trusted builder
- Citizens Advice — Before you get work done on your home
General information only, not legal or financial advice. Last checked 2026-09-30.
