Guides · Bookkeeping · 7 min read · Updated 25 September 2026
Bookkeeping for small builders: progress claims, subbies, variations and what the accountant needs
A building job is not one invoice; it is a deposit, several progress claims, a few variations, a dozen subbie invoices and a final. The books have to hold all of that against one job, or the profit on the job is a guess. Here is the routine that keeps it straight.
One job, many documents
Set the job up once, from the accepted quote. Every progress claim, variation, subbie payment and materials purchase is recorded against that job. At any point you can see what has been claimed, what has been spent and the margin so far, which is the number that tells you whether to keep quoting the same way.
Progress claims
- Agree the stages in the quote: for example deposit, slab, frame, lock-up, fit-out, completion, with a percentage each.
- Each claim is its own tax invoice, numbered, referencing the quote and the stage.
- Record the payment against the claim when it lands, so the job shows what is outstanding at every stage.
- Domestic building contracts in most states cap the deposit and set rules for progress payments; check your state's building authority.
Variations
In writing, priced, accepted before the work starts, and recorded against the job as their own document. A variation that lives in a text message is an argument at the final claim.
Subcontractors and TPAR
Every subbie payment needs their ABN, the invoice, the amount and the date, recorded separately from other expenses, because the ATO wants the annual total per contractor on the Taxable Payments Annual Report, due 28 August. If a subbie will not give you an ABN, you are generally required to withhold tax at the top rate. Ask before the first job.
The routine
Daily: enter materials and subbie invoices against the job as they arrive, receipt attached. Weekly: raise the claims that are due, record payments, chase the late ones. Monthly: reconcile against the bank and check each open job's margin. Quarterly: BAS. Annually: TPAR by 28 August and the workbook to your accountant.
What your accountant needs
Income by month with GST, expenses by category with GST, subcontractor totals with ABNs, an asset list, vehicle kilometres and your BAS lodgements. Work in progress at 30 June matters for builders: know which jobs are open and what has been claimed on each. SmokoBooks exports the year as one Excel workbook and shows every job's claimed and spent totals.
Common questions
Do I need job costing software?+
You need costs recorded against jobs. That can be a spreadsheet for one job at a time; once you have three jobs open, an app that does it as a matter of course is what stops things being missed.
Are deposits income?+
For tax and GST purposes a deposit is generally reported when it is received or invoiced, depending on your accounting method. Your accountant can confirm which applies to you.
Which subbie payments go on TPAR?+
Payments for building and construction services, including invoices that mix labour and materials. Materials-only invoices are excluded.
General information for Australian sole traders and small trade businesses, not tax or legal advice. Thresholds, rates and due dates change: confirm the current figures on ato.gov.au or with your accountant.