How much deposit should I pay a builder in Northern Ireland?

The honest answer is that a reputable NI builder on a typical domestic job often needs no deposit at all, established firms have accounts with their merchants. Where a deposit is legitimate is bespoke, made-to-order items: a custom staircase, made-to-measure windows, a specific kitchen. Even then it should be proportionate to those materials, not a percentage of the whole contract, and it should be in writing.

The structure that protects you is stage payments: the job broken into milestones, foundations, walls up, roof on, first fix, completion, with a payment released as each stage is actually finished. Money follows completed work, so at no point are you significantly exposed. Trading Standards NI guidance and FMB-style contracts both push this pattern, and any established builder will recognise it without offence. Our hiring-safely guide includes a worked stage-payment schedule you can copy.

The red flags are the mirror image: pressure for a large upfront payment, cash-only demands, round numbers with no written scope, or a discount that only exists if you pay today. A builder who needs your money to start your job is telling you something about their business, and it is not something good.

Before any money moves: written quote with full scope and dates, proof of public liability insurance, and two references you actually phone. Five minutes of checking beats months of chasing.