The building and construction industry sits at the centre of two of the ATO's most active compliance programs: the Taxable Payments Reporting System and the cash economy audit program. Bookkeepers servicing tradies carry responsibility for ensuring both obligations are met — the penalties for non-compliance fall on the business, not the accountant, but the oversight failures that lead to those penalties are often bookkeeping failures.
TPAR Obligations for Building and Construction
Businesses in the building and construction industry must lodge a Taxable Payments Annual Report by 28 August each year if, during the income year, they: (a) carry on a business in the building and construction industry, and (b) make payments to contractors for building and construction services. The threshold for lodgement is lower than for other sectors — the requirement applies if any payments at all are made to contractors for building services, regardless of amount, provided the business itself is in the building and construction industry.
The categories of building and construction services covered by TPAR are broad: they include bricklaying, carpentry, concreting, electrical work, excavation, installation of building fixtures, painting, plastering, plumbing, roofing, tiling, and waterproofing. Landscaping and cleaning services are also in scope as separate TPAR categories.
The bookkeeper must maintain a contractor payment register throughout the year capturing each contractor's name, ABN, address, and gross payments (including GST). Attempting to reconstruct this information from bank records at year end is unreliable. A subcontractor who has not provided their ABN should have a withholding notation in the register — the 47% no-ABN withholding rules under Division 12 of Schedule 1 to the TAA 1953 apply where a contractor fails to quote their ABN.
Materials vs. Labour: GST and Quote Structuring
A plumber or electrician who supplies materials and installs them makes a mixed supply of goods (the materials) and services (the labour). For GST purposes, both components are taxable at 10% — there is no materials exemption. The total GST-inclusive quote is the base for calculating the 1A liability.
For cost management and client transparency, quotes should separate materials and labour. This separation is not a GST requirement but a practical necessity: the bookkeeper needs to track materials costs against the bill of materials for each job to identify over-runs, and the client may query component pricing. Fixed-price contracts that bundle labour and materials produce a single revenue line; the bookkeeper should still record the materials used from inventory against the job so that gross margin by job type can be analysed.
Materials purchased for stock — not yet allocated to a specific job — are inventory, not an expense. Expensing materials on purchase and failing to recognise unsold or uninstalled inventory on hand at year end will overstate COGS and understate closing inventory. For tradies with significant materials holdings (e.g., electrical contractors who stock cable, fittings, and switchgear), the inventory misclassification can be material.
Work Vehicle Expenses and Log Books
A ute, van, or dual-cab used exclusively or predominantly for work purposes — transporting tools, equipment, and materials to job sites — is a work vehicle. The costs of a work vehicle, including fuel, oil, tyres, servicing, registration, insurance, and loan interest (or lease payments), are fully deductible where there is no private use.
Where there is some private use, the deductible proportion must be determined by a log book covering a continuous 12-week period that is representative of the vehicle's use pattern. The log book records each trip's date, destination, odometer readings, and purpose. The work-use percentage established by the log book applies for 5 years unless the use pattern changes materially. For employees who use an employer-provided vehicle, the FBT implications must also be assessed — the operating cost method or the statutory formula method determines the FBT liability on any private use component.
For a sole trader tradie, the vehicle expense deduction is claimed in the income tax return. For a company that owns the vehicle and allows an employee (including a director) to use it privately, the FBT implications are unavoidable unless the vehicle is a ute or dual-cab used primarily for carrying tools and materials with only incidental private use — the ATO's guidance on primary-use utes provides that genuinely work-oriented vehicles with minimal private use may qualify for the work-related exemption under s.47(6) of the FBTAA 1986.
Trade Licences and Insurance as Deductible Expenses
Licence fees, annual registration renewals for trade qualifications, and professional membership subscriptions are deductible business expenses under s.8-1 ITAA 1997. Public liability insurance, contractor's all-risk (CAR) insurance, and professional indemnity insurance premiums are similarly deductible in the year the premium is paid, subject to the prepayment rules.
For small business entities (turnover below $10 million), prepayments for services that will be provided entirely within 12 months of the payment date are deductible in the year of payment under the SBE prepayment exception in s.82KZM ITAA 1997. An annual insurance premium paid on 1 June and covering the period to 31 May the following year is fully deductible in the June year for an SBE. For non-SBE businesses, the deduction must be apportioned — only the current-year portion is deductible, with the balance as a prepayment asset.
Cash Payments and the ATO's Cross-Referencing Capacity
The ATO's construction-sector data matching program is one of its most effective compliance tools. When a builder pays a plumbing subcontractor in cash and neither party reports the transaction, the ATO identifies the anomaly by cross-referencing the builder's TPAR (which should report the payment) against the subcontractor's tax return income. Missing TPAR entries, or income reported in returns that does not match TPAR data, generate ATO risk flags.
The risk to the bookkeeper's client is not limited to the primary tax evasion consequence. The ATO's benchmark program publishes industry-specific gross profit and expense-to-turnover ratios. Tradies with ratios outside the benchmark range are flagged for review. A plumbing business with unrecorded cash income will show an abnormally low revenue-to-assets ratio and abnormally low income relative to industry comparisons.
Bookkeepers should ensure all income is invoiced through the practice management or accounting system, regardless of the payment method. Cash received that is not run through the system is not a bookkeeping preference issue — it is a tax fraud risk for the client.