Let’s be honest, a builder’s books are nothing like a typical business. Standard accounting just can’t keep up with the organised chaos of progress claims, retentions, subbies, and materials spikes. True construction accounting Australia 2025 is a whole different ball game, built from the ground up to track project profitability from day one. This guide delivers a practical, plain-English breakdown covering GST on progress claims, WIP, payroll/STP, TPAR, and cash flow – essentials for staying on the right side of the ATO, which is watching the industry closely.
The Basics – How Construction Accounting Differs from Regular Bookkeeping
If you’ve ever felt like your standard accounting software doesn’t quite ‘get’ your business, you’re not wrong. It’s not designed for the unique financial rhythm of a building project.
The core differences really boil down to a few key areas:
- Long-Running Projects: You don’t earn your revenue in one hit. It’s recognised over the life of the project, which is tied to complex rules like AASB 15 (Australian Accounting Standards Board). This means your profit isn’t simply this month’s sales minus this month’s costs.
- Job Costing & WIP Drive Profit: The real engine room of your profitability is tracking every single dollar- materials, labour, subbies, and plant hire against each specific job. This isn’t just bookkeeping; it’s the financial blueprint of your project, known as job costing. This feeds into Work-in-Progress (WIP) reports.
- Cash vs. Profit Timing: Progress claims, deposits, variations, and those pesky retentions create a huge gap between the cash sitting in your bank and the actual profit you’ve made. Relying on your bank balance is one of the fastest ways for a builder to get into serious trouble.
- Cash vs. Accrual Choice Matters: Whether you report your income and expenses for BAS purposes on a cash or accrual basis has big implications for your cash flow. A progress claim issued but not yet paid could mean you owe the ATO GST before you’ve even received the money.
Current ATO Rules for 2025–26 (What Builders Must Know)
The ATO and state revenue offices have specific rules for the construction industry. Staying on top of them is non-negotiable for anyone serious about construction accounting Australia 2025. Here are the essentials:
- GST Registration Threshold: Once your GST turnover hits $75,000, you must register for GST. For most builders, this happens on day one.
- BAS Cycle: You’ll lodge your Business Activity Statement (BAS) either monthly or quarterly. The basis you choose (cash or accrual) directly impacts when you report GST on progress claims. Get advice from our BAS/GST services team.
- STP Phase 2: Single Touch Payroll (STP) Phase 2 requires you to report detailed payroll data to the ATO with every pay run. This includes breaking down payments like allowances, overtime, and apprentice wages. Your W1/W2 figures on the BAS must reconcile with your STP lodgements.
- Super Guarantee: From 1 July 2025, the super guarantee rate increases to 12%. Pay it on time. Late super triggers the Superannuation Guarantee Charge (SGC), which is harsh and non-tax-deductible.
- TPAR (Taxable Payments Annual Report): If you pay contractors for building and construction services, you must lodge a TPAR by 28 August each year, detailing their ABN, name, address and total payments.
- Payroll Tax: This is a state-based tax on your total wages once you exceed a certain threshold. The rates, thresholds, and rules around deeming contractors as employees vary by state. See the table below for 2025 thresholds.
- Records: You must keep all key records- invoices, timesheets, contracts, evidence of variations, and retention agreements – for 5 to 7 years.
Disclaimer: Rates and thresholds are subject to change. Always verify current figures with the ATO or your relevant state revenue office before acting.
Job Costing & WIP – The Heart of Construction Accounting
Getting your hands dirty with job costing and Work-in-Progress (WIP) reports is where you find out the real profit on every single job. These aren’t just fancy terms; they’re the most powerful tools in a builder’s financial kit.
- Job costing is the nitty-gritty process of tracking every single cost- from a box of screws to a subcontractor’s invoice – and tying it directly to a specific job. Without job costing for builders, you’re just guessing which projects are making you money.
- WIP (Work-in-Progress) takes that job costing data and tells you if you’re over-billed (cash flow is good, but is it profitable?) or under-billed (you’re funding the client’s project). This is the cornerstone of WIP accounting Australia.
Worked Example: WIP Calculation
Let’s see it in action. You’re building a home with the following numbers:
- Contract Price: $440,000 (including $40,000 GST) → $400,000 ex-GST
- Estimated Total Cost: $300,000
- Costs to Date: $180,000
- Calculate Percentage Complete:
% Complete = Costs to Date / Estimated Total Cost% Complete = $180,000 / $300,000 = 60%
- Calculate Revenue to Recognise (ex-GST):
Revenue = Contract Price (ex-GST) x % CompleteRevenue = $400,000 x 60% = $240,000
- Calculate Gross Profit to Date:
Gross Profit = Revenue Recognised - Costs to DateGross Profit = $240,000 - $180,000 = $60,000
Now, compare this to what you’ve billed. If you’ve billed the client $275,000 (incl. GST) so far, you are over-billed by $25,000 ($250,000 ex-GST vs $225,000 revenue recognised). This is good for cash flow but needs to be tracked.
Example WIP Schedule
| Job | Contract (ex-GST) | Costs to Date | % Complete | Revenue to Date | Billings to Date | Over/(Under) Billed |
|---|---|---|---|---|---|---|
| Job 101 | $400,000 | $180,000 | 60% | $240,000 | $250,000 | $10,000 |
| Job 102 | $750,000 | $400,000 | 53% | $397,500 | $350,000 | ($47,500) |
| Job 103 | $300,000 | $285,000 | 95% | $285,000 | $300,000 | $15,000 |
As you can see, Job 102 is significantly under-billed, meaning your business is carrying the cost of that $47,500 shortfall.
Progress Claims, Deposits, Variations & Retentions (with GST)
Getting paid in construction is a multi-step process, and each step has specific GST rules that can easily trip you up on your BAS.
- Progress Claims & GST: When you issue a progress claim, you must account for the GST on the full taxable amount of that invoice in that BAS period. If you are on an accrual basis, this is payable to the ATO whether the client has paid you or not.
- Deposits: A deposit is generally a pre-payment, triggering GST liability in the period you receive it or issue the invoice, whichever comes first.
- Variations: Every variation must be documented with scope, price, and GST. It should be invoiced properly to update your contract value and WIP report.
- Retentions: This is a major trap. Even if cash is withheld, the GST on the full original invoice is still payable.
Retention GST Example
You issue a progress claim for $110,000 (including $10,000 GST). The client withholds a 10% retention ($11,000).
- Cash received: $99,000
- GST payable to the ATO for this period: $10,000
You cannot net off the retention. You are liable for the full $10,000 GST upfront. This is a critical aspect of retentions accounting.
GST Recognition and BAS Reporting Table
| Item | When GST is Recognised (Accrual Basis) | BAS Boxes |
|---|---|---|
| Deposit | In the period the payment is received or invoice issued, whichever is first. | G1 / 1A |
| Progress Claim | In the period the invoice is issued. | G1 / 1A |
| Variation | In the period the invoice for the variation is issued. | G1 / 1A |
| Retention Held | GST is recognised on the full invoice value when first issued. | G1 / 1A |
Payroll & Subbies – STP, Super and Contractor Rules
Your team is your biggest asset, but managing payroll and subbies is riddled with compliance traps. Getting your construction bookkeeping Australia right is non-negotiable.
Employees (including apprentices)
For direct employees, STP Phase 2 is mandatory. With every pay run, you report detailed data to the ATO, correctly categorising items like overtime, site allowances, and bonuses. Super is payable at 12% from 1 July 2025. Our Bookkeeping/Payroll services can handle this for you.
Contractors
Just because a tradie has an ABN doesn’t automatically make them a contractor in the eyes of the ATO. If a contractor is paid mainly for their labour, they can be “deemed” an employee for super purposes, meaning you’re liable.
Safety Note: The ATO uses a multi-factor test to identify sham contracting. They check who has control, who supplies tools, and if the work can be delegated. Get this wrong and face massive penalties.
Finally, all payments to contractors for building services must be reported on the TPAR construction report due 28 August.
BAS for Builders – Cash Flow Tactics
Managing your Business Activity Statement (BAS) is more than a compliance task- it’s a cash flow tool.
Choosing Cash vs. Accrual
- Accrual Basis: You report GST when an invoice is issued. This gives a truer picture of profitability but can mean you pay GST on money you haven’t received yet (e.g., on a progress claim with a long payment term).
- Cash Basis: You report GST only when cash is received. This is better for short-term cash flow, especially if you have slow-paying clients, but can mask underlying profitability issues.
Monthly BAS Checklist
A disciplined monthly process is key for every builder.
- Reconcile all bank feeds.
- Code all expenses correctly (job costs vs. overheads).
- Capture and attach all receipts and supplier invoices.
- Update your WIP schedule.
- Reconcile STP payroll lodgements to your payroll system.
- Set aside GST and PAYG Withholding into a separate tax savings account.
- Check supplier statements for missing invoices.
Payroll Tax for Construction
Payroll tax is a state tax on wages paid once you exceed a threshold. Rules on contractor deeming and grouping related businesses are complex and vary by state.
| State/Territory | 2025 Annual Threshold (Est.)* | Headline Rate (Est.)* |
|---|---|---|
| NSW | $1,200,000 | 5.45% |
| VIC | $900,000 | 4.85% (regional 1.2125%) |
| QLD | $1,300,000 | 4.75% (4.95% for payroll >$6.5M) |
| SA | $1,500,000 | 4.95% |
| WA | $1,000,000 | 5.5% |
| TAS | $2,000,000 | 6.1% (4% for payroll <$2M) |
| ACT | $2,000,000 | 6.5% |
| NT | $1,500,000 | 5.5% |
Callout: These figures are based on 2024-25 data. Verify current thresholds and rates with your respective State Revenue Office before acting.
Tools & Integrations Builders Actually Use
The right tech stack can be a game-changer. The core accounting platforms like Xero, MYOB, and QuickBooks are your financial engine. They become powerhouses when integrated with industry-specific job management software like Buildxact, CoConstruct, AroFlo, simPRO, ServiceM8, Fergus, or Tradify.
For a full breakdown, check out our guide to the best accounting software for tradies/builders.
What Should Sync?
- Jobs and cost codes
- Purchase Orders (POs) and delivery dockets
- Timesheets and labour costs
- Invoices and receipts
Top Tip: Before going live, run a full test. Create a dummy job and follow its data flow from quote → PO → delivery docket → progress claim. This ensures your data is bulletproof.
Common Mistakes
- Treating Retentions as a Discount: Under-remitting GST because you only received partial payment is a classic error that the ATO finds easily.
- No Job Codes: Mixing project materials with general overheads makes it impossible to know if a job is profitable.
- Ignoring WIP: Relying on your bank balance is a recipe for disaster. Your cash might look great, but the job could be losing money.
- Late Super: Paying super late triggers the non-tax-deductible Superannuation Guarantee Charge (SGC). It’s pure, painful loss.
- Not Filing TPAR: Failing to lodge your TPAR or using poor contractor data (wrong ABN/Name/Address) is a major red flag for the ATO.
- Picking the Wrong BAS Basis: Choosing the wrong basis (cash vs. accrual) for your business model can destroy your cash flow.
- Not Reviewing Payroll Tax: Forgetting to check thresholds and grouping rules annually can lead to a surprise tax bill.
Mini Case Studies
- Small Builder Fixes Cash Flow: A residential builder was struggling with lumpy cash flow. By switching to monthly BAS lodgements and more frequent progress invoicing, they smoothed out their GST payments and got a real-time view of their financial position via their WIP report.
- Renovator Finds Profitability: A renovation firm couldn’t figure out why profits were so low despite being busy. After implementing proper cost codes and holding a weekly WIP meeting, they identified two types of jobs that were consistently losing money and adjusted their quoting.
- Contractor Avoids Audit: A commercial contractor was flagged by the ATO for messy contractor payments. By tightening their subcontractor onboarding process (getting correct ABNs and details upfront) and implementing a system for TPAR data collection, they cleaned up their reporting and avoided a costly audit.
FAQs
Do builders need to register for GST in Australia?
Yes, almost certainly. If your business has a GST turnover of $75,000 or more, you must register for GST. Given the cost of materials and labour, virtually all professional builders will exceed this threshold.
How do I account for retentions and progress claims for GST?
You must report and pay GST on the full taxable value of your progress claim in the period you issue the invoice, regardless of whether a retention amount has been withheld. You cannot reduce the GST payable just because you received less cash.
What is WIP accounting and why does it matter?
WIP (Work-in-Progress) accounting is a method used to calculate the real-time revenue and profit on your unfinished projects. It’s vital because it prevents you from confusing cash in the bank with actual job profitability, giving you a true picture of a project’s financial health.
Do I need to lodge a TPAR for subcontractors?
Yes. If your business is primarily in the building and construction industry and you pay subcontractors for services, you must report these payments to the ATO annually on a Taxable Payments Annual Report (TPAR). The due date is 28 August each year.
Should a builder use cash or accrual accounting?
While both have pros and cons, the accrual method generally provides a more accurate picture of a project’s profitability over time. However, the cash basis can be better for managing BAS cash flow if you have slow-paying clients. The best choice depends on your business size and structure; professional advice is recommended.
When does super apply to contractors mainly for labour?
Under ATO rules, if you engage a contractor and the contract is principally for their personal labour and skills, they may be considered an ’employee’ for superannuation purposes, even if they have an ABN. You would be required to pay superannuation guarantee on their behalf.
Conclusion
Proper construction accounting Australia 2025 hinges on mastering WIP, GST timing, payroll/STP compliance, and TPAR discipline. Getting it right is the foundation of a profitable and sustainable building business.
At Nanak Accountants & Associates, we set up builder-grade job costing, WIP, BAS/TPAR and payroll so you stay compliant and profitable. Call 1300 NANAK TAX (626 258) or book a consult with our Business Advisory team.
