For educational purposes only. Not tax, legal, or financial advice. Tax laws change frequently. Consult a registered tax agent or CPA for your specific situation.
Australian plumbers pay income tax on trading profit (sole trader) or company tax at 25% base rate (Pty Ltd). GST registration is compulsory at $75,000 turnover. If you pay subcontractors for construction work, you must lodge a TPAR by 28 August each year, and SG obligations apply on labour-only subcontractor payments at the current 12% rate (2025-26).
Last reviewed:
Guidance, not advice. We explain the rules, we don't assess your situation. Always seek financial or tax advice from your accountant, or contact ATO. Read our editorial scope →
Australian plumbers need a state-issued plumbing licence before quoting a single job, and the licensing body differs in every state. Tax obligations layer on top: income tax on trading profit (sole trader) or company tax at 25% (Pty Ltd base rate entity), GST registration once turnover hits $75,000, TPAR lodgement if you pay subcontractors for construction services, and potential SG obligations on labour-only subbies. The right structure depends on profit level, liability exposure on gasfitting work, and whether you run a crew or work solo.
What business structure do Plumbers use?
The common patterns for Plumbers are: Sole trader: simplest setup, ABN registration only, suits one-person operators under roughly $100k profit, Pty Ltd company: limited liability for gas and water work, access to 25% base rate entity tax, salary-plus-dividend extraction from around $100k+ profit, Partnership or trust: less common in plumbing, occasionally used for family businesses or income-splitting arrangements (s.100A risk applies to non-arm's-length distributions). The right structure depends on revenue, liability exposure, and personal circumstances, covered below.
How does TPAR apply to Plumbers?
Plumbers paying subcontractors for building and construction services may need to lodge a Taxable payments annual report. See the dedicated TPAR mechanics below.
How does TPAR apply to plumbing businesses?
If your business is primarily in building and construction (50%+ of income or activity), has an ABN, and makes payments to subcontractors for construction services, you must lodge a Taxable Payments Annual Report (TPAR) by 28 August each year. The report lists total payments to each contractor: name, ABN, gross amount, and GST component.
The ATO cross-matches TPAR data against subcontractor tax returns to detect undeclared income. Late or missing TPARs are a current compliance focus, and the ATO has started issuing penalties for late lodgement. If you engage subbies for any construction work, assume TPAR applies.
Businesses primarily in building and construction that pay contractors must lodge TPAR by 28 August, reporting each contractor's ABN, gross payments, and GST.(TAA 1953 Schedule 1 Division 396; ATO guidance ATO building and construction TPAR guide)
Do I owe super on subcontractor payments?
If you engage an individual contractor (not a company or trust) and the contract is wholly or principally for their labour rather than a supply of materials or equipment, you must pay Superannuation Guarantee on the labour component at the current SG rate (12% for 2025-26).
The test: is more than 50% of the invoice for labour? If yes, SG is required on the labour portion. If most of the invoice covers materials, plant hire, or equipment, and labour is under 50%, SG usually does not apply. Do not pay SG on the GST component or separately itemised materials.
Many plumbing subbies who provide only their labour, hand tools, and small consumables will attract SG obligations for the head contractor. This catches businesses that treat subbies as independent when the economic substance is employment.
Contractors engaged principally for labour (not materials or equipment) are deemed employees for SG purposes; the payer must contribute SG at the current rate on the labour component.(SGAA 1992 s 12(3); ATO guidance ATO super for contractors guide)
When do I need to register for GST?
GST registration is mandatory once your annual turnover reaches $75,000 (or $150,000 for non-profit entities). Turnover means gross business income, not profit. Many established plumbers hover near this threshold and risk crossing it during a busy period with material-heavy commercial jobs.
Voluntary registration below the threshold lets you claim GST credits on materials, tools, and vehicle expenses. The trade-off: you charge 10% GST on every invoice and lodge Business Activity Statements (BAS) quarterly or monthly.
For plumbers doing a mix of domestic (no GST charged to homeowners if unregistered) and commercial work, crossing the threshold mid-year triggers a 21-day registration window. Late registration attracts penalties and backdated GST on all invoices from the date you should have registered.
GST registration is compulsory when annual turnover reaches $75,000. Voluntary registration is available below this threshold.(A New Tax System (Goods and Services Tax) Act 1999 s 23-15; ATO guidance ATO GST registration guide)
What can plumbers claim for vehicle expenses?
Two methods: cents-per-km (88 cents per business kilometre, capped at 5,000 km, giving a maximum $4,250 deduction) or the logbook method (actual running costs multiplied by business-use percentage from a 12-week representative logbook).
For full-time plumbers running multiple jobs per day with tools permanently stored in the vehicle, logbook method almost always gives a larger deduction. Running costs include fuel, servicing, registration, insurance, tyres, cleaning, interest on finance, and decline in value.
Vehicle type matters: passenger vehicles (including many dual-cab utes under 1-tonne payload) are subject to the car depreciation limit of $69,674 for 2025-26. Vehicles designed to carry more than 1 tonne or 9+ passengers (typical 1-tonne tray utes, some commercial vans) are not subject to the car limit, and decline in value is worked out on full cost, still capped by business-use percentage.
Decision rule: if your work vehicle's payload exceeds 1 tonne or seats 9+, no car limit applies. Otherwise the $69,674 cap limits your depreciation claim.
Vehicle expenses can be claimed via cents-per-km (88c/km, max 5,000 km) or logbook method (actual costs x business-use %). Passenger vehicles are subject to the car depreciation limit.(ITAA 1997 Division 28 (car expenses) and Division 40 (decline in value); ATO guidance ATO vehicle and travel expenses guide)
Contractor vs employee: the written contract is decisive
The High Court reset the contractor/employee test in 2022. Where there is a comprehensive written contract that is not a sham, classification turns principally on the rights and obligations established by that contract — not on the day-to-day conduct of the parties. Get the engagement contract right at the start; do not rely on post-contract behaviour to recharacterise the relationship later.
This matters because misclassification exposes the engager to PAYG withholding shortfalls, super guarantee charge (with the contractor-deemed-employee extension under SGAA 1992 s 12(3)), and payroll tax. It also affects whether the worker can deduct business expenses and whether PSI rules engage.
Contractor vs employee classification is determined principally by the rights and obligations in the written contract, not by post-contract conduct.(CFMMEU v Personnel Contracting Pty Ltd [2022] HCA 1; ZG Operations Australia Pty Ltd v Jamsek [2022] HCA 2 (companion case); ATO guidance TR 2023/4 (employee vs independent contractor))
Home running costs: PCG 2023/1 fixed-rate vs actual cost
Most workers in this trade do some admin from home — quoting, invoicing, scheduling, BAS prep. From 1 July 2024 the ATO fixed-rate method is 70c per hour worked from home and covers electricity, gas, internet, mobile, stationery and computer consumables. You cannot also claim those bills separately under the fixed rate. You can still separately depreciate office furniture and equipment used at home.
FY 2024-25 and FY 2025-26 rate: 70c/hr. FY 2022-23 and FY 2023-24 rate: 67c/hr. The fixed rate requires a contemporaneous record of actual hours worked from home — a timesheet, calendar or app log. Estimates and four-week samples are no longer accepted for the fixed rate method (they remain valid for the actual cost method).
The fixed-rate method for home office running costs is 70c per hour from 1 July 2024 and requires a record of actual hours worked from home.(PCG 2023/1 (as amended); ITAA 1997 s 8-1; ATO guidance TR 93/30; TR 2024/3)
Plumbing union dues, Master Plumbers membership, HIA membership
Deductible as professional membership
Vehicle and travel costs
Most full-time plumbers should use the logbook method: keep a 12-week representative logbook, then apply the business-use percentage to all running costs for the year. For a plumber running 4-5 jobs per day with tools stored in the vehicle, business use is typically 70-90%. The logbook is valid for five years unless circumstances change significantly. Cents-per-km (88c/km, max 5,000 km) is simpler but caps the deduction at $4,250, which rarely covers actual costs for a full-time tradesperson. A ute with payload over 1 tonne avoids the $69,674 car depreciation limit entirely.
Capital allowances and equipment
The instant asset write-off threshold for small business entities (turnover under $10 million) is $20,000 per asset for 2025-26. A $15,000 drain camera, a $3,500 pipe locator, or a $2,000 set of press-fit tooling can each be written off in full in the year of purchase. For assets above $20,000 (or if the instant write-off is not available), the simplified depreciation pool applies: 15% in the first year, 30% in subsequent years. A $50,000 work ute for a sole trader (above the car limit if it is a passenger vehicle) would be depreciated at cost minus business-use apportionment through the pool.
Common ATO audit triggers for Plumbers
High vehicle claims without a logbook to substantiate business-use percentage
TPAR mismatch: head contractor reports payments to your ABN that exceed your declared income
Cash jobs not declared (ATO cross-references bank deposits, lifestyle indicators, and industry benchmarks)
Large tool and equipment claims without receipts or an asset register
Repeated business losses claimed against other income without meeting non-commercial loss tests (Division 35)
Private expenses claimed as business (home renovation materials purchased through the business account)
Frequently asked questions
Do I need to lodge a TPAR if I only do domestic plumbing?+
Only if you pay subcontractors for construction services. If every job is done by you alone for homeowners, TPAR does not apply. The moment you engage a subbie for construction work and your business is primarily in building and construction, TPAR kicks in. Lodge by 28 August each year.
Is my plumbing licence renewal fee tax deductible?+
Yes. Annual state plumbing licence renewals, gasfitting endorsements, backflow prevention accreditation fees, and professional association memberships are fully deductible as ongoing trade expenses. Your initial apprenticeship or qualifying training to become a plumber is not deductible as it is considered personal capital expenditure.
Should I use cents-per-km or logbook for my work ute?+
Logbook for most full-time plumbers. Cents-per-km caps at 5,000 business kilometres ($4,250 maximum deduction), which rarely covers actual costs for a tradesperson running multiple jobs per day. A 12-week logbook establishes your business-use percentage (typically 70-90% for plumbers), then you claim that percentage of all actual running costs for the year. The logbook is valid for five years unless your work pattern changes significantly.
Do I need to pay super for my subcontractors?+
If the subcontractor is an individual (not a Pty Ltd or trust) and the contract is principally for their labour rather than a supply of materials or equipment, you must pay SG at 12% (2025-26) on the labour component. If most of the invoice covers materials, plant hire, or equipment and labour is under 50%, SG generally does not apply. Many plumbing subbies who provide only their labour and hand tools will attract SG obligations.