Quote-to-invoice flow
Quote-to-invoice flow: estimate, quote, contract, progress claim, variation, invoice. Each step is a control point. Built right, it's the engine of builder profitability.
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The flow from “client requests a quote” to “final invoice paid” has 7-9 control points: estimate, quote/tender, contract, deposit, progress claims, variations, practical completion, defects-period invoices, final retention release. Most builders nail the front (estimate and quote) and back (final invoice) but lose money in the middle: variations not captured, progress claims served late or defectively, retention forgotten. The fix is a documented, repeatable flow where each step’s output is the next step’s input.
The full flow
Lead → Estimate → Quote → Contract → Deposit invoice → Progress claims
↓
Variations
↓
Practical completion invoice
↓
Defects period invoices
↓
Retention release invoiceEach step is described below as a process.
Step 1: Lead intake
A new lead comes in (referral, web form, direct call). Capture:
- Client name, contact details.
- Property address (essential for licensing, scope, planning checks).
- Scope description in client’s words.
- Budget signal (if disclosed; if not, ask once and move on).
- Time signal (when do they want to start, when do they want to finish).
- Source (where the lead came from, for marketing tracking).
Store in a CRM or even a spreadsheet. Don’t lose leads in email or memory.
Step 2: Estimate
The internal cost-build for the project. This is NOT the quote; it’s the calculation the quote is derived from. Tool of choice for residential: Buildxact, ServiceM8, or similar takeoff/estimating software.
Estimate structure:
| Section | Typical % of total cost |
|---|---|
| Materials | 35-45% |
| Labour (trades) | 30-40% |
| Site costs (delivery, skip bin, scaffold, fence) | 5-8% |
| Compliance and approvals | 1-3% |
| Overheads (builder’s office, vehicles, insurance) | 8-12% |
| Profit margin | 15-25% (typical residential) |
| Contingency | 5-10% |
Cost library and trade rates plug in here. Output: total cost-built figure that the quote is built FROM.
Step 3: Quote / tender
The client-facing document. Includes:
- Project description and inclusions.
- Exclusions (essential, save arguments later).
- Quoted price (GST inclusive in residential B2C).
- Validity period (typical 30 days).
- Payment terms (stage schedule).
- Assumptions (e.g. “based on assumed slab Class M; H1 or higher will require variation”).
- Conditions of acceptance.
Quote is NOT the contract; quote acceptance triggers contract drafting.
Step 4: Contract
The legal agreement. In residential, typically a state-standard HIA or MBA form, or a custom form if the build is over the state’s mandatory threshold.
Contract documents include:
- The signed contract form.
- Quote / specification as a schedule.
- Plans and drawings.
- Stage payment schedule.
- Variations procedure.
- Defects liability and retention terms.
Signing the contract triggers deposit invoice.
Step 5: Deposit invoice
Typical residential: 5% of contract value (some states cap this; NSW caps deposit at 10%, Vic at 5% for contracts over $20k, similar elsewhere).
Issue invoice immediately on contract signing. Don’t wait for the first stage to start.
Step 6: Progress claims
For each construction stage, a progress claim (payment claim under the relevant Security of Payment Act) gets served:
- Stage completes; certifier signs off where applicable.
- Issue payment claim on the contract reference date (or per the SOPA in the relevant state).
- Payment claim must:
- Identify the work done.
- Claim a specific amount.
- Reference the relevant Security of Payment Act (state-specific).
- Be served correctly (email, post, hand delivery per contract).
- Client has the contract-specified period to pay (typically 10-15 business days for residential).
- If client disputes, they must serve a payment schedule explaining what they’ll pay.
- If neither paid nor scheduled, the claimed amount becomes a statutory debt.
Common builder errors:
- Generic invoice instead of SOPA-compliant claim. Loses statutory enforcement leverage.
- Claim served on wrong date or to wrong address. Restart the clock.
- Claim doesn’t identify work or amount clearly. Disputable.
Step 7: Variations
A variation is a documented change to the contract. Process:
- Client (or builder) requests a change.
- Variation form drafted with: scope description, cost impact, time impact, payment terms.
- Client signs the variation before the work is started.
- Variation work proceeds.
- Variation invoice issued per the variation terms (typically billed at the next stage payment).
Why this matters: variations not documented at the time become disputes later. The builder did the work, the client says they didn’t approve it.
State law varies on the formality:
- NSW (Home Building Act): residential variations must be in writing, signed.
- Vic (Domestic Building Contracts Act): same.
- Qld (Domestic Building Contracts Act): same.
Verbal variations are legally binding in most cases BUT enforcement is far harder. Don’t do verbal.
Step 8: Practical completion invoice
When the build reaches Practical Completion (PC):
- Issue PC notice to the client.
- Client has the contract period (typically 10 days) to inspect and respond.
- Once accepted, issue the PC invoice for the PC stage payment.
- Defects identified at PC are scheduled, not invoiced.
PC invoice typically also bills any outstanding variations.
Step 9: Defects period and retention release
Defects period (typical 3-6 months on residential):
- Defects list at PC; builder rectifies during defects period.
- Retention (if held) typically 5% of contract value; sometimes 2%.
- Retention release invoice issued at end of defects period after final inspection signs off no outstanding defects.
State HBI / HBA / DBI schemes specify minimums on residential.
Common builder errors
| Error | Cost |
|---|---|
| Generic invoice not SOPA-compliant | Loss of statutory enforcement; longer recovery cycle |
| Variations done on a handshake | Disputed and unpaid at end-of-job |
| Progress claim served late | Cashflow gap; gap interest cost |
| Wrong reference date | Defective claim; needs re-issue |
| Practical completion invoice held back | Unnecessary cashflow gap |
| Retention forgotten | $5k-$30k of unbilled income |
| No deposit invoice | Front-loaded working capital strain |
Tools
- Estimating: Buildxact, ServiceM8, Cubit.
- Accounting: Xero, MYOB, Buildxact integrated.
- Document signing: DocuSign, signed PDF + email evidence chain.
- CRM: Buildxact built-in, ServiceM8, HubSpot.
- Contract management: HIA / MBA standard contract templates.
A good builder runs the entire flow inside 2-3 connected tools (estimating + accounting + signed-document chain), not 6-7 disconnected ones.
For builders
- Document the flow: write down what triggers each step. Don’t keep it in your head.
- Use a SOPA-compliant payment claim template for every progress claim. Get it right once, use forever.
- Variations: written, signed, before work starts. The cost of a 5-minute admin task pre-work is zero; the cost of a disputed verbal change post-work is potentially the value of the change plus legal cost.
- Diary the dates: contract reference dates, defects period end, retention release. Missing any of these costs money.
- Reconcile estimate to actual at each stage. If material costs are running 10% over estimate, you need to know before the next quote uses the same numbers.
References
- ATO GST and tax invoice requirements: https://www.ato.gov.au/Business/GST/Tax-invoices/ (verified 2026-05-15).
- NSW Fair Trading Home Building: https://www.fairtrading.nsw.gov.au/housing-and-property/building-and-renovating (verified 2026-05-15).
Related
See also
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Last updated: 2026-05-15. Verified: 2026-05-15.