Contracts and payments
The contract sum, the scope of works and a payment schedule that looks after itself — plus what the client sees, and why they see it.
Updated 15 September 2026
Disagreements on a domestic job are almost never about whether the window went in. They are about whether it was in the price, what a provisional sum means, and why you are asking for twelve grand on a Tuesday. All three are answered by three things written down at the start — and once they are written down, BuildFlow keeps them in step with the work.
- A contract sum, with the VAT and retention position stated.
- A scope of works — what the price covers, what it doesn't, and what is only an allowance.
- A payment schedule, where each stage is tied to a milestone or a date.
All of it lives on the project's Money tab. Your client sees the same tab, called Payments, with the same figures and none of the buttons.
Setting the contract terms
Open a project, go to Money, and press Set the contract sum. Four figures, three of which usually look after themselves.
| Field | What it means | Usual answer |
|---|---|---|
| Contract sum | The agreed price, excluding VAT | Whatever you quoted |
| VAT rate | A percentage: 20 means 20% | 20 if you are VAT registered, 0 if not — and 0 for zero-rated work |
| Retention | Money held back until the defects period ends | 0 on most domestic jobs; 2.5–5% on larger ones |
| Payment terms | Days from a stage falling due to payment being expected | 14 |
VAT defaults from your company
Tick VAT registered in Company settings and every new project starts at 20%. New build and some conversions are zero-rated, so you can still set a project to 0 without touching the company setting.
Don't edit the contract sum when a variation is agreed
The sum recorded is the ORIGINAL, and it is meant to stay that way — it is the figure both of you signed. Absorbing a change into it destroys the evidence that the change was agreed, which is the one thing your client will want to see when they query the final bill. Raise it as a change instead; the money screen shows the original, the approved changes and the current sum side by side.
The scope of works
Three sections, because they answer three different questions. A client reading the first is asking what they are getting; reading the third, what it might end up costing.
| Section | For | Carries a figure? |
|---|---|---|
| Included | Work the contract sum pays for | No |
| Not included | Work it does not — said out loud now, not argued about later | No |
| Provisional sum | An allowance, not a price | Yes |
The lines you leave out of Not included are the ones argued about in month three. Tiles, kitchen units, appliances, decorating, skips, scaffold over a neighbour's garden, making good the drive — if it is not in your price, it belongs here.
Why provisional sums are worth the extra line
A provisional sum is the single most misunderstood line in a domestic quotation. Your client reads £2,500 for sanitaryware as a price; you mean it as an allowance. BuildFlow labels it as an allowance and says so on the client's screen and in the handover pack, so the conversation when the real cost lands is about a choice they made, not about a surprise you sprung. Link a decision on the Choices tab to the allowance and it will do the subtraction for you.
The payment schedule
Each payment says what makes it payable. That is the difference between a schedule that maintains itself and a list you have to remember to update.
| What makes it due | Use it for | What happens |
|---|---|---|
| When a milestone is ticked | Stage payments — slab down, watertight, first fix | Ticking the milestone on the timeline makes the payment due, dates it from your terms, and tells the client |
| On a date | Anything the contract fixes to a calendar date | It shows as due once the date arrives |
| When I say so | Deposits, and anything you would rather decide yourself | Nothing happens until you press the button |
- 1
Add the payment
Give it a name a client will recognise — “Deposit”, “Slab down”, “Practical completion”.
- 2
Type the amount, or the percentage
Builders write schedules both ways. Type into either box and the other follows; only the pounds figure is stored, so the two can never drift apart.
- 3
Say what makes it due
Pick the milestone, or the date, or leave it manual.
- 4
Let the job do the rest
Tick “Slab down” on the timeline and the stage payment falls due, dated 14 days out, with your client notified from the same act rather than by a phone call that feels like it came out of nowhere.
Written the schedule up mid-job?
A payment tied to a milestone you have already ticked starts out due rather than sitting at “not yet due” forever. Schedules get typed up in week six as often as in week one.
Moving a payment along
| State | Means | Who moves it |
|---|---|---|
| Not yet due | The trigger hasn't happened | — |
| Due | It is payable | The milestone, the date, or you |
| Invoiced | You have raised an invoice for it | You — the client is told |
| Paid | The money arrived | You — the client is told |
A payment can go straight from due to paid without passing through invoiced. Plenty are settled by bank transfer on the day the slab goes down, and making them pass through an invoice state would be bookkeeping theatre.
Record what actually arrived
Marking a payment paid asks you for the amount, pre-filled with what you asked for. When a client pays £16,000 of a £17,000 stage — because they hired the skip themselves, or rounded it — record the £16,000. The difference stays in what the job is owed rather than quietly disappearing from your totals.
Un-ticking a milestone you ticked by mistake takes its payment back to not-yet-due. It stops at invoiced: once an invoice has gone out, the way back is a credit note, not an undo.
Changes to the job
Anything agreed after the contract sum was set is a change, priced and decided on its own record. Approved changes move the contract sum; nothing else does.
What your client sees
The same figures, in their own language, on a tab called Payments. Agreed price, paid so far, due now, left to pay — plus the whole schedule and the whole scope of works. What they do not get is any control over it.
Showing them is the point. A scope only you can see is a scope your client will dispute; a payment schedule only you can see is a phone call every time a stage falls due. One number that both of you are looking at is worth more than any amount of explaining. Nobody else sees it — employees and subcontractors have no access to the contract sum, the schedule or the changes, because what you charge your client is between you and your client.
One thing only you see
If your schedule doesn't add up to the contract sum, BuildFlow says so — on your screen, not theirs. £500 short is usually a typo; £12,000 short is usually the final payment nobody has written down yet.
Where the figures turn up
- Your dashboard — contracted, received, due now and outstanding, across your live jobs only. Completing or archiving a job takes it out of the total.
- The project overview — three figures and the next payment, for both of you.
- The handover pack — a contract page with the sum, VAT, retention, the scope of works and the full payment schedule with what actually arrived against each stage. It is the page a homeowner still has in five years when they sell the house.
What isn't here yet
BuildFlow does not handle CIS, and it does not take the money — there is no card payment and no "pay now" button, which is a choice rather than a gap. CIS is coming. Raising the invoice itself is built: see the invoicing guide.
Which plans have it
Basic and above. The free tier is a trial of running one job; a contract with a payment schedule is the point at which somebody is running a business.