The scope of work is the document
A contractor’s estimate wins or loses the job, and then spends three weeks being the reference everyone argues from. A price with no scope of workbehind it is a number the customer will compare against someone else’s number, and nothing else.
Scope means being specific about three things:
- What is included. Room by room, item by item, in the order the work will happen.
- What is excluded. The lines that stop an argument: making good beyond the work area, disposal of items not listed, anything discovered behind a wall.
- What it assumes. That the substrate is sound, that access is available between certain hours, that the customer supplies the fittings.
Break the price across those items rather than giving one figure. A customer comparing two quotes will pick the one they can understand, and a broken-down estimate also gives you somewhere to put a change later without rewriting everything.
Deposits
On anything involving materials or a held date, a deposit is normal — commonly a quarter to a third, taken when the job is confirmed. Two things make it work smoothly:
- State it on the estimate,as an amount and as a condition. “A 30% deposit ($1,620) confirms the booking and covers materials ordering” is clearer than “deposit required”.
- Show it on the final invoice. Full total first, then the deposit already received, then the balance. An invoice that shows only the balance looks like it is for a smaller job than the one you quoted, and that discrepancy is exactly what a customer notices.
Change orders
Every job of any length changes. The difference between a change order and an argument is whether the change was written down before the work happened.
It does not need to be a form. A message on the day — what changed, what it costs, and a request to confirm — creates the record. What it must have is a price and a reply. “I’ll sort it out at the end” is how a $600 extra becomes a dispute in week three.
On the invoice, each change goes on as its own line, dated and described as agreed. Keep them below the original estimate lines so the customer can read the document in two halves: what we agreed, and what changed.
Subcontractors
If you bring in an electrician or a plasterer, decide up front whether their work appears as a line on your invoice or whether they bill the customer directly. Mixing the two on one job is how somebody ends up unpaid.
Billing a subcontractor’s work through your own invoice is usually cleaner for the customer — one document, one payment, one person accountable. Put it on as a described line (“Electrical: consumer unit replacement and certification”) rather than as a bare pass-through, because from the customer’s side it is part of your job.
Example
Final invoice against a three-week estimate
Estimate lines first, in the order they were quoted. Changes below, dated. Deposit applied last.
- Strip out existing bathroom and disposePer estimate EST-0031
- $1,150.00
- First and second fix plumbingPer estimate EST-0031
- $2,400.00
- Wall and floor tiling, 14 m²Per estimate EST-0031
- $1,820.00
- Electrical: extractor and lighting circuitSubcontracted, includes certification
- $780.00
- Change: replace corroded soil stack sectionAgreed 14 July, quoted before work
- $465.00
- Subtotal
- $6,615.00
- Tax (5%)
- $330.75
- Total
- $6,945.75
- Deposit received 28 June
- −$1,984.50
- Balance due
- $4,961.25
Invoice INV-0233 · Issued 2 August · Due 16 August. Line items 1–3 correspond to estimate EST-0031 dated 24 June. The soil stack section was quoted and confirmed by message on 14 July.
Make the two documents reconcilable
This is the single most useful habit in contractor invoicing. Your customer will, at some point, hold the estimate next to the invoice and try to make them agree. Help them:
- Keep the estimate’s line order on the invoice.
- Use the same wording for the same item.
- Reference the estimate number on the invoice.
- Put everything that was not on the estimate below everything that was.
The general principles behind both documents are in invoice vs estimate, and invoice numbering explains why the two sequences should stay separate — quotes that never convert would otherwise punch holes in your invoice numbers.
Where Invoice Tiger fits, and where it stops
It handles the documents: estimates with expiry dates, invoices with due dates, separate EST- and INV- sequences, a deposit field that subtracts from the total to show a balance due, line items with quantities and rates, and a tax rate on the document. Everything renders as a PDF with your own logo on it.
It is not construction software. There is no project scheduling, no job costing against budget, no Gantt anything, no lien or compliance handling, no crew management, no photo documentation, and no accounting. For a two-person operation that mostly needs the paperwork to be right, that is the point. For a business running six jobs and a payroll, it is not enough, and you should buy something bigger.
One clarification worth making: the deposit field records an amount you have already been paid so the document shows the correct balance. It is part of the document, not payment tracking — nothing here knows whether money arrived.