Plumbing regulators in each state want a record that licensed work was done properly. For STC purposes, that record becomes part of the evidence pack. The rules are state-based, so what follows is a guide to the pattern, not legal advice. Check your regulator’s current page.
Victoria
Plumbers issue a Compliance Certificate for prescribed plumbing work through the Victorian Building Authority system, generally within days of completion, and the owner receives a copy. The regulator’s guidance on heat pump installations is worth reading before your first Victorian job. The Victorian Plumbing Regulator, via the Building and Plumbing Commission, also publishes industry updates on heat pumps.
New South Wales
NSW requires a Certificate of Compliance for plumbing and drainage work, and hot water installation is plumbing work that only licensed plumbers can do. Certificates are lodged through the NSW system and the owner gets a copy. If you are also claiming ESCs, see NSW stacking.
Queensland
Queensland uses a Form 4 compliance certificate for notifiable plumbing and drainage work under the Plumbing and Drainage Act 2018. The plumber is responsible for completing and lodging it with the relevant authority.
Other states
Western Australia, South Australia, Tasmania, the ACT and the NT have their own plumbing regulators and paperwork. If you work across borders, keep a short note of each regulator’s certificate name and timing.
What matches what
| Document | Must agree on |
|---|---|
| Compliance certificate | Address, date, plumber details |
| Assignment form | Owner name, address, date |
| Invoice | Model, serial, install date |
| Photos | Serial, install location, date metadata |
From the desk: the most common mismatch is the certificate date. If the certificate is issued a week later, that is fine, but the installation date on the invoice and photos should still be the day the unit went in.
What this means for installers
Treat the certificate as a gate. No certificate where one is required, no lodgement. It takes a minute to attach and avoids a resubmission. The hot water and heat pump checklist puts it in the full list, and how STC audits work shows why records are kept. For rates and settlement, see pricing, how it works and the hot water STC pillar.
Keeping the certificate with the job
File the certificate in the same folder as the assignment form, photos and invoice, named by address and install date. If the regulator or your trader asks for it months later, you can answer straight away. Give the owner their copy as the regulator requires, and keep your own for as long as your records obligations run. Checking the retention period is worth five minutes on the regulator’s website.