How much deposit should you pay a builder?

Deposits are normal and reasonable - a builder often needs to buy materials or book in specialist trades before work starts. The question is what "reasonable" looks like, and where it tips into a red flag.

What's typical

For most residential jobs, a deposit in the region of 10-25% of the total cost is common, often specifically to cover the cost of materials that need ordering upfront. For larger projects, it's increasingly common to agree a staged payment schedule instead - a smaller deposit followed by payments tied to completed milestones (e.g. after first fix, after plastering, on completion) rather than one large sum upfront.

When to be cautious

• A deposit above 30-50% of the total, with no clear material-cost justification, is worth questioning.
• Pressure to pay in cash only, with no invoice or paper trail, removes your ability to dispute anything later.
• A demand for the full amount upfront before any work starts is a significant warning sign - a legitimate builder is financing their own labour and time as the job progresses, not asking you to fund the entire job before they've proven anything.
• No written record of what the deposit covers - always get it in writing (even a simple email confirmation) alongside the quote.

Staged payments protect both sides

A payment schedule tied to milestones is usually the fairest structure: it means the builder isn't working unpaid for weeks, and you're never more than one stage's worth of money exposed if something goes wrong. It's a completely normal thing to propose if a builder's own quote doesn't already suggest one.