A stage payment schedule ties each payment to work you can actually see and check on site, rather than to dates or promises. A sensible schedule also holds back a final retention until any defects found after completion have been put right.
The principle: payment follows visible progress
The safest payment schedule is one where you never owe more money than the value of work already standing in front of you. Each payment should be triggered by a stage you or an independent person can actually verify — foundations poured, walls up to a certain height, roof watertight — rather than by a date on a calendar.
This protects both sides properly. The builder is paid promptly for completed work rather than waiting until the very end for everything, and you are never significantly out of pocket relative to what has actually been delivered on site.
Illustrative schedule: a small job
For smaller jobs — a bathroom refit, re-roofing, a set of internal alterations — a shorter schedule of three or four payments over a few weeks is usually proportionate. The figures below are illustrative only and will vary hugely with the job.
| Stage | Trigger | Illustrative amount |
|---|---|---|
| Start | Materials on site, strip-out begins | £2,000 |
| First fix | Plumbing and electrics first fix complete | £3,000 |
| Second fix | Tiling and fittings complete, tested and working | £3,000 |
| Retention | Held 2–3 weeks after completion for snagging | £1,000 |
Illustrative schedule: a single-storey extension
Larger projects need a longer schedule with more stages, because a much bigger sum of money is at stake and each stage represents genuinely different, checkable work.
| Stage | Trigger | Illustrative amount |
|---|---|---|
| Start on site | Groundworks begin, materials delivered | £8,000 |
| Foundations & slab | Building Control inspection passed | £8,000 |
| Walls to roof height | Brickwork/blockwork complete to wall plate | £10,000 |
| Roof watertight | Roof structure and covering complete | £10,000 |
| First fix | Plumbing, electrics, plastering complete | £9,000 |
| Second fix & completion | Kitchen/bathroom fitted, decorated, tested | £7,000 |
| Retention | Held 4–6 weeks after handover for defects | £3,000 |
Valuation-based versus fixed-milestone schedules
On larger jobs, some contracts use a valuation approach — an agreed person (sometimes an architect or surveyor, sometimes both parties by agreement) assesses the value of work completed to date at intervals, and payment matches that valuation. This is more flexible than fixed milestones but relies on both sides trusting the valuation, or appointing someone independent to do it.
A fixed-milestone schedule, as in the tables above, is simpler for smaller domestic jobs because the stages are unambiguous — the roof is either on or it isn't. It is usually the more practical choice unless you have a professional already involved in overseeing the works.
Retention and the defects period
A retention is a final slice of the contract price, commonly in the region of a small percentage of the job, held back after the work looks finished and released once a defined defects period has passed and anything found has been fixed. This gives you real leverage to get snagging sorted rather than chasing a builder who has already been paid in full.
Agree the retention amount and the length of the defects period in writing before work starts, not after completion when there is nothing left to negotiate with.
What to check before releasing each payment
Before paying any stage, physically look at the work, or have someone competent look at it on your behalf, rather than relying on a phone call or a photo sent by the builder. Check that materials specified in the quotation have actually been used, that the stage matches what was agreed, and that there is nothing obviously wrong that you'd want fixed before more money changes hands.
Where a stage includes work that will be covered up shortly afterwards — drainage, insulation, structural fixings — this is the point to check, because it becomes far harder and more expensive to verify once it is hidden behind plasterboard or under a slab.
Front-loaded schedules: a warning sign
A schedule where the early stages are priced heavily and the payments taper off towards the end is a red flag. It suggests the builder wants to be paid well ahead of the value of work delivered, and it leaves you with the least leverage exactly when defects are most likely to surface — at the end of the job.
As a rough sense check, compare what proportion of the total contract price has been paid at each stage against what proportion of the physical work has genuinely been completed. They should track each other reasonably closely throughout the job.
Putting the schedule in the contract
Whatever schedule you agree, it should appear in writing as part of the contract or quotation, not as a separate verbal understanding. See our quote checklist guide for what else a proper written quotation should include alongside the payment schedule.
Practical checklist
- Agree the full payment schedule in writing before work starts
- Tie every payment to a specific, checkable stage rather than a date
- Compare the proportion paid so far against the proportion of work actually done
- Physically check or arrange for someone to check work before paying for it
- Pay particular attention to stages that are about to be covered up
- Agree a retention amount and defects period in writing from the outset
- Be wary of schedules that are heavily front-loaded
- Keep a written or photographic record of progress at each stage
- Get a receipt or invoice for every stage payment
- Check that materials used match what was specified in the quotation
- Confirm what happens to the schedule if the job runs later than planned
- Agree how variations or extra work will be priced and paid separately
- Check whether Building Control sign-off is a trigger point for any payment
- Ask what recourse you have if a stage is paid for but later found defective
- Know who to contact if a payment dispute arises mid-project
- Keep all payment schedule correspondence together with the contract
Good and bad examples
What good looks like
A written schedule of six stages tied to physical milestones — groundworks, walls to roof height, roof watertight, first fix, second fix and completion, and a final retention — with each payment matched roughly to the proportion of work actually delivered, and a 5% retention held for six weeks after handover.
What to push back on
A verbal agreement to pay '25% now, 25% in two weeks, the rest at the end', with no reference to what stage of work should have been reached at each point, and 75% of the money paid before the roof is even on.
Worked example
Illustrative example only: how paid-to-date can track work-done-to-date on a £55,000 extension
| Point in project | Cumulative paid | Approx. work completed |
|---|---|---|
| After foundations | £16,000 (29%) | ~25% of job |
| Roof watertight | £36,000 (65%) | ~60% of job |
| Completion, pre-retention | £52,000 (95%) | ~95% of job |
| After defects resolved | £55,000 (100%) | 100% of job |
Commonly missed items
- No written schedule at all, only a verbal understanding
- Payments tied to dates rather than to verifiable stages
- No retention or defects period agreed before work starts
- No plan for how variations will be priced within the schedule
- No record kept of what stage had actually been reached at each payment
Warning signs
- A schedule that is heavily weighted towards the early stages of the job
- Requests to bring payments forward of the agreed schedule
- Pressure to pay for a stage before it is visibly complete
- No retention offered or discussed at all
- Reluctance to put the payment schedule in writing
- Invoices that don't match the stages originally agreed
Questions to ask
- Can you set out the full payment schedule in writing before we start?
- What exactly needs to be finished on site to trigger each payment?
- What retention will you agree to, and for how long after completion?
- How will extra work or variations be priced and paid separately?
- What happens to the schedule if the job overruns?
- Who do I contact if I think a stage isn't ready to be paid for?
When to seek professional advice
- If a builder pushes back hard against any form of retention
- If you're unsure whether a stage genuinely matches what's been paid for, consider an independent inspection
- If a payment dispute escalates, Citizens Advice can explain consumer rights routes, including small claims
- For Building Control-related sign-off queries, contact your local authority Building Control team
Official sources
Frequently asked questions
- How many stage payments should a building project have?
- It depends on the size and length of the job. A short job might have three or four stages; a longer extension often needs six or more so that no single payment covers too large a chunk of work you haven't yet seen.
- What is a retention in a builder's payment schedule?
- A retention is a portion of the total price held back after the work looks complete, released once a defined defects period has passed and any snagging has been fixed. It gives you leverage to get problems resolved before the builder has all the money.
- Is it normal for a builder to ask for payment weekly?
- Some builders invoice weekly for labour and materials as the job progresses, which can be reasonable on longer jobs provided each invoice reflects work genuinely completed that week. It should still be set out in the written schedule, not sprung on you partway through.
- What should I do if I've already paid more than the work completed is worth?
- Raise it directly and in writing straight away, referring back to the agreed schedule. The longer an imbalance is left, the harder it becomes to correct, so it's worth checking progress against payments at every stage rather than waiting until the end.
- Can a payment schedule change once work has started?
- It can, by agreement, but any change should be confirmed in writing at the time, including what it means for the retention and final balance, rather than left as a verbal adjustment.
Builder Proof UK publishes general educational information for homeowners. It is not legal, structural, surveying, planning, electrical, gas, insurance or financial advice, and it does not replace advice from a suitably qualified professional for your specific project.