Almost every plumbing horror story starts the same way: a rushed decision made under pressure, no written quote, and a licence nobody checked. All three are avoidable in about ten minutes.
This checklist covers verifying that a plumber is actually licensed, getting quotes you can genuinely compare, and the red flags that should end a conversation early.
Step one: verify the licence, every time
Plumbing is licensed in every Australian state and territory, and every register is publicly searchable online for free. Ask for the licence number and check it: that the licence is current, that the name matches the person or company quoting, and that the licence class covers the work (water, sanitary, gas fitting and drainage are separate classes in most states).
The registers are run by Consumer and Business Services in SA, the Victorian Building Authority, NSW Fair Trading, the QBCC in Queensland, and the plumbers licensing board in WA. Searching takes under a minute. A legitimate plumber expects the question; hesitation or excuses are your answer.
Getting quotes you can actually compare
Two quotes for the same job are only comparable if they cover the same scope. Get every quote in writing, itemised into labour, materials, callout and GST, and confirm three things: is it a fixed price or an estimate, what happens if the scope grows, and does it include clean-up and disposal.
For anything beyond a few hundred dollars, collect two or three quotes. The spread will surprise you, and the conversation with each plumber tells you nearly as much as the number does.
Compliance certificates: your proof the work was legal
For notifiable work, which includes gas fitting, hot water installation, drainage and most work beyond simple repairs, the plumber must lodge a certificate of compliance with the state regulator and give you a copy. This document matters: it is your evidence for insurance claims, warranty disputes and when you sell the property.
Ask before the job starts whether the work is notifiable and confirm you will receive the certificate. A plumber who dodges this question is telling you how they operate.
Red flags that should end the conversation
None of these is illegal on its own. Two or more together is a pattern:
- Cash-only pricing, or a discount for skipping the paperwork
- No licence number on the website, vehicle or quote
- Large deposit demanded before any materials are ordered
- Quote delivered only verbally, or a written quote with a single line and no breakdown
- Pressure tactics: today-only pricing, or discovering urgent extra problems mid-job without showing you evidence
- No fixed business address or landline, and reviews that mention repeated no-shows
Payment terms that protect both sides
For small jobs, payment on completion is standard. For larger jobs, a modest deposit with progress payments tied to milestones is normal; paying the full amount up front is never justified.
Keep every document: the quote, invoices, receipts, the compliance certificate and photos of the work. If a dispute does arise, your state's consumer affairs body or civil tribunal will want exactly that paper trail, and having it usually means you never need them.
Frequently asked questions
What is the difference between a plumber and a gas fitter?+
They are separate licence classes, though many tradespeople hold both. If your job involves any gas appliance, line or connection, verify the gas fitting licence specifically, not just a general plumbing licence.
Does a plumber's work come with a warranty?+
Yes, twice over. Australian Consumer Law guarantees services are provided with due care and skill, and materials come with manufacturer warranties. Many states also mandate defect liability periods for notifiable plumbing work. Keep your invoice and compliance certificate as proof.
Should I use the cheapest quote?+
Not automatically. A quote far below the others usually excludes something: materials, disposal, compliance certification or a realistic assessment of the job. Ask the cheap quoter what is not included, and ask the expensive one why. The answers usually make the decision for you.