Do I Need a Licensed Plumber in WA?

In Western Australia, yes — you almost always need a licensed plumber. By law, plumbing work on the drinking water, sewerage and drainage systems must be carried out by a licensed plumber, and all gas work must be done by a licensed gas fitter. This is regulated by Building and Energy and the Plumbers Licensing Board. DIY on drinking water or gas isn't just risky — it's illegal, and it can void your insurance and endanger your household. Here's what that means in practice.

What legally requires a licensed plumber?

Most plumbing beyond the very simplest tasks must be done by a licensed professional in WA. That includes:

Any work on drinking (scheme) water supplied by the Water Corporation — installing, altering or repairing pipes and connections
Sewerage and drainage work, including connecting and clearing drains beyond a simple plunge
Installing or replacing fixtures like toilets, hot water systems, taps and mixers where it involves the water supply
Hot water system installation — electric, gas, solar or heat pump
Backflow prevention and rainwater connections to the mains

The reason is public health and safety. Poorly done work on drinking water can contaminate the supply; badly connected drainage can leak sewage. Licensing exists to make sure the person doing the work knows the standards.

Gas work: always a licensed gas fitter

Gas is even stricter. In WA, all gas fitting — installing, altering, repairing or connecting gas appliances and lines — must be done by a licensed gas fitter. There's no small-job exception. Natural gas (supplied in Perth by ATCO) and LPG are explosive and can produce carbon monoxide when appliances burn incorrectly. A single mistake can cause a fire, explosion or poisoning.

That covers connecting a gas cooktop, installing a gas hot water system, running gas lines, and any gas plumbing and fitting. If you ever smell gas, don't investigate it yourself — follow our gas leak safety guide and call a licensed gas fitter.

What can I legally do myself?

Only very minor maintenance that doesn't touch the water supply, drainage or gas. Depending on the exact task, that generally means things like:

Replacing a tap washer or a shower head
Clearing a simple blockage with a plunger
Changing a toilet seat

Anything more — new pipework, a hot water unit, moving a fixture, or any gas work — needs a licensed professional. If you're ever unsure whether a job crosses the line, the safe assumption is that it does. A quick call to a plumber costs nothing to ask.

It's worth being clear that "it's only a small job" is not an exception the law recognises. The rules are about the type of work — anything touching drinking water, drainage or gas — not the size of it. A small mistake on a drinking-water connection can contaminate your supply just as easily as a big one, and a minor gas error can be just as dangerous. That's exactly why the licensing system exists.

The risks of unlicensed work

Cutting corners with an unlicensed "handyman" or DIY can cost far more than it saves:

It's illegal. Unlicensed plumbing and gas work can attract penalties under WA law.
Your insurance may not pay out. If a leak, flood or fire is traced to unlicensed work, your insurer can refuse the claim.
Safety. Gas mistakes risk explosion and carbon monoxide; water mistakes risk contamination, flooding and damage.
No compliance and no warranty. Licensed work comes with a compliance certificate and consumer protections. Unlicensed work has neither.
Problems at resale. Non-compliant work can be flagged in inspections and become your problem when you sell.

What about renters and landlords?

The licensing rules apply no matter who owns the property, but the responsibility for arranging repairs usually sits with the landlord or their agent. If you're renting and something needs plumbing or gas work, report it to your property manager rather than attempting it yourself or hiring someone directly — the landlord is generally responsible for maintaining the property's plumbing and for using a licensed professional. For landlords, using licensed tradespeople isn't just good practice; it protects you if a tenant is ever harmed by faulty work, and it keeps your insurance valid.

How to check a plumber's licence in WA

It's easy to verify that a plumber or gas fitter is properly licensed:

Ask for their licence details. A legitimate professional will happily provide them.
Check with Building and Energy. WA's Building and Energy (Department of Energy, Mines, Industry Regulation and Safety) maintains licence registers you can search to confirm a plumber or gas fitter is current.
Confirm the right licence for the job. A plumbing licence and a gas fitting licence are separate — make sure they hold the one that covers your work.
Get everything in writing, including a quote and, on completion, the relevant compliance paperwork.

Our guide on choosing a plumber goes deeper into what else to look for beyond the licence.

The bottom line

For almost any plumbing job — and every gas job — in WA, you need a licensed professional. It keeps you legal, keeps your insurance valid, and keeps your household safe. The small saving from unlicensed work rarely survives the first problem. When you use a licensed Canning Vale plumber, you get compliant work, proper paperwork and genuine peace of mind.

Not sure if your job needs a licensed plumber? Call our licensed Canning Vale plumbers and just ask — we'll tell you straight.

Frequently asked questions

Do I legally need a licensed plumber in WA?

For almost all plumbing, yes. Work on drinking water, sewerage and drainage must be done by a licensed plumber, and all gas work by a licensed gas fitter. It's regulated by Building and Energy — DIY on drinking water or gas is illegal and unsafe.

What plumbing can I legally do myself in WA?

Only minor maintenance that doesn't touch the water supply, drainage or gas — like replacing a tap washer, changing a shower head or clearing a simple blockage with a plunger. Anything more, including any gas work, requires a licensed professional.

What happens if I use an unlicensed plumber?

Unlicensed plumbing and gas work can breach WA law, void your insurance if something goes wrong, come with no compliance certificate or warranty, and create safety risks. It can also cause problems when you sell the property, so it rarely saves money.

How do I check if a plumber is licensed in WA?

Ask for their licence details and verify them through Building and Energy, which maintains searchable licence registers. Make sure they hold the correct licence for your job — plumbing and gas fitting are separate — and get all paperwork in writing.