There's no legal cap on how much deposit a builder can ask for, but the guidance is consistent: the Federation of Master Builders says around 10% is often used as a guide on larger projects, and Citizens Advice says not to agree to more than 25%. On a short job with no special-order materials, there's often no good reason for a deposit at all.
What a deposit is actually for
A legitimate deposit covers costs the builder has to commit before starting — usually materials, and especially made-to-order items like windows, doors, kitchens or steelwork that can't be returned. It isn't payment for work not yet done. Ask exactly what the deposit covers, make sure it's written into the contract, and get a receipt. If the answer is vague, treat that as the answer.
Offer to buy the materials yourself
If the deposit is for materials, Citizens Advice suggests offering to buy them yourself instead. You then own them outright if anything goes wrong, rather than having paid someone else to buy them. Many builders get trade discounts, so this can cost slightly more — but it removes the biggest risk a deposit creates.
Pay in stages, never ahead of the work
Beyond any deposit, pay in stages tied to finished parts of the job — foundations done, walls up, roof on, first fix complete — agreed in writing before work starts. Each payment should roughly match the value of work actually completed. Keep a meaningful final payment back until everything is finished and any snagging is sorted, because that's your leverage to get the last details put right.
How you pay matters as much as how much
Pay by card where you can, and avoid cash. If you pay by credit card for a job costing between £100.01 and £30,000, you may be able to make a section 75 claim against the card provider if things go wrong — and that includes a deposit paid on the card, even if the deposit itself is under £100. Debit cards offer the voluntary chargeback scheme. Bank transfers have neither protection, so if you pay that way, confirm the account details by phone before sending anything, and be very wary of a message saying the builder's bank details have changed mid-project — a classic scam.
Deposit protection and escrow
Some builders offer insurance-backed deposit protection, which returns your deposit if they go out of business, or use an escrow service that holds your money in a neutral account and releases it at agreed stages. Neither is universal, but it's worth asking — a builder who offers one is signalling that they expect to finish the job.
Frequently Asked Questions
Is a 50% deposit normal for building work?
No. That's double the 25% Citizens Advice says not to exceed, and five times the FMB's usual guide. Ask what it's for — if there's no clear answer tied to specific materials, look elsewhere.
Does a builder need a deposit for a small job?
Often not. Both the FMB and Citizens Advice frame deposits around larger projects and materials bought upfront. For a short job with standard materials, paying on completion is common.
Can I get my deposit back if I cancel?
If you agreed the contract at home or away from the builder's premises, you may have a 14-day cooling-off period. After that, the builder can usually keep an amount that reflects their genuine loss — but not necessarily the whole deposit, and it's worth negotiating if the amount seems unreasonable.
Where this information comes from
- Federation of Master Builders — How to choose a builder
- Citizens Advice — Before you get work done on your home
- Citizens Advice — Cancelling building or decorating work
General information only, not legal or financial advice. Last checked 2026-09-30.
