Skip to content
Calculators Guides The app Privacy Pricing Get early access
Home Guides PlumbersLicences, gas & backflow
2
Plumbers tax guide › Chapter 2 of 6

Plumber licences: plumbing, gas and backflow

By the PFO team, to our editorial standards ·Last reviewed August 2026

Plumbers tax guide — chapter two

There is as much paperwork in plumbing as there is pipe. A plumbing registration to keep current, a gas work licence up for renewal, backflow accreditation due for its next revalidation, a confined-space refresher, TAFE invoices during an apprenticeship. Which of these you can claim comes down, almost every time, to one distinction. Money spent to stay in the trade you already work, or to get sharper at it, tends to count. Money spent to break into the trade, or to cross into a different one, does not. Regulators and scheme names vary state to state; the tax treatment is the same nationwide.

The initial-versus-renewal line

Here is the distinction that costs plumbers the most, and it runs both ways. The licence or registration that lets you enter the trade or first take on a role isn't deductible, because at that point no plumbing income exists to attach it to, so getting in is a cost you carry. Renewals flip it: once the licence is in your hand and you renew it to carry on your current job, the renewal is deductible.

Not deductible

The first plumbing registration that let you begin, and an initial gas work licence. Entering the trade is a different thing from working in it.

Deductible

Renewing the plumbing or gas licence you already hold, through your state regulator, to keep doing the job you're in.

Whether your regulator is the QBCC in Queensland, the VBA in Victoria or Fair Trading in New South Wales, the outcome is identical from one side of the country to the other. It's not the name on the letterhead that decides it, but whether the fee keeps you qualified for work you're already doing.

Gas tickets and backflow revalidation

Gas and backflow are where a plumber's recurring tickets stack up, and once you hold them, both fall cleanly on the deductible side of the renewal line.

Renewing the gas work licence.The first gas authorisation, the one that added gas to your scope, isn't claimable. Renewing it to keep doing gas work in your current role is.
Revalidating backflow accreditation.Backflow prevention accreditation needs periodic revalidation, and because you already hold the role, each revalidation is deductible.
The revalidation course.The course you sit to revalidate backflow is self-education for the job you're already doing, so its fee rides on the same logic and comes off too.
The first gas ticket buys your way into gas work. Every ticket after it buys your way to stay, and only the second kind is yours to claim.

Confined space and the white card

The safety tickets that get you into pits and under floors follow the same initial-against-renewal split.

The first white card is out.The general construction induction card that first cleared you onto a site came before any income, so like the initial licence, it isn't deductible.
Refreshers and renewals are in.A confined-space refresher, or renewing any ticket you hold to keep doing your current work, is deductible.
Extra tickets that build on the role.An added ticket that extends the plumbing job you already do, rather than moving you into a different one, is deductible.

Your driver's licence

A driver's licence never makes the return, new or renewed, even though a plumber plainly can't reach a job without one. The ATO files it as a private, everyday cost that everyone bears, and plumbing gets no exception. Keep it well clear of the gas and backflow renewals, because it doesn't sit with them.

Self-education tied to your work

Study earns a deduction where it holds up or sharpens the skills your current plumbing job uses, or stands to raise the income you make from it. Where that thread holds, you can claim course, tuition and student fees, textbooks and stationery, and the travel to and from where you study.

What qualifies.Course and enrolment fees, textbooks and stationery, and self-education travel, when the study connects to the plumbing you already do, say a backflow, gas or thermostatic mixing valve course.
The catch.Study to get into the trade, or to jump to another occupation, isn't deductible, and neither is a course only loosely linked to your work. Handy and deductible are not the same thing.
The loan is off-limits.Study-loan repayments never come off, HELP or an Apprenticeship Support Loan alike. Fees you pay directly can qualify; the repayments on a loan cannot.

Apprentices and the Cert III

An apprentice plumber stands on firmer ground than someone switching careers, and the reason is worth understanding. Since an apprentice already works in the trade while studying it, the Certificate III maintains and improves the skills of the job they hold, so the link to current employment is met.

What you can claim.Self-funded TAFE or course fees, textbooks and stationery, and tools for the apprenticeship under the $300 rule, with each item of $300 or less deducted straight away.
Only your own money.Where the employer pays for the course, or it comes through a government loan, that part isn't yours. Claim only what left your own pocket, the stationery, the transport from work to TAFE.
Travel.The leg from work to TAFE and back is deductible. Home to TAFE and back is treated as an ordinary commute, so that part is private.

An apprentice on a low wage may owe little tax in the first place, so these deductions won't always come back as a refund. Keeping the records is still worthwhile, but a deduction can't return money that was never withheld.

The records that hold these up

These claims run on paper, and it's the paper easiest to lose, because it never arrives all at once: a renewal notice one month, a backflow revalidation the next, a TAFE invoice partway through a semester.

  • Renewal notices for the plumbing, gas or safety tickets you renew.
  • Backflow revalidation and course receipts tied to your current role.
  • Course invoices and receipts for study linked to your current work.
  • A brief note connecting each cost to your current job, since that link is what the ATO actually tests.
PFO+ Tax

PFO+ Tax files every licence renewal, backflow revalidation and course invoice against the right claim the moment it arrives, encrypted and held in Australia, so nothing sits waiting for a shoebox come July.

See the Tax Pack →

The bottom line

Put every licence, ticket and course cost to the one test: are you paying to keep doing the plumbing you work now, or to do it better? If so, and you funded it and can show the record, it belongs on the return. Claim the plumbing and gas renewals, the backflow revalidation and its course, the refreshers, the study that sharpens your current work. Leave off the first plumbing or gas licence, the first white card, and the driver's licence. Get the apprentice rules right and you keep every dollar that staying qualified genuinely costs you.

Add up your deductions

See what your licence renewals, backflow revalidation, study costs and fees come to at tax time.

Deductions calculator →

General information only, not tax advice. Check the ATO or a registered tax agent for your situation.

Official sources

Figures on this page follow primary Australian Government sources, verified for 2026-27:

Get early access →

PFO flags your work deductions as you spend, all year, then builds an accountant-ready Tax Pack. First access, and founding pricing.

Join the waitlist Try a calculator first →