What the online check tells you
The NSW Government lists plumbing, drainage and gasfitting among the specialist work that needs a licence regardless of its cost. Its licence check shows the holder’s name, licence numbers, categories and expiry dates, and also:
- what type of licence or certificate is held, and its current status;
- any cancellation or suspension under the Home Building Act 1989 or the Fair Trading Act 1987;
- any conditions on the licence, public warnings, formal cautions, penalty infringement notices and failures to comply with a related tribunal order;
- the results of prosecutions under the Home Building Act in which the holder was found guilty.
Why drainage is its own line on a licence
The categories of plumbing, draining and gasfitting work are described in schedule 4 of the Home Building Regulation 2014. Two matter most for the pipes under a house:
- Plumbing
- It “includes water plumbing, sewerage and sanitary work. It does not include draining work or roof plumbing.”
- Draining
- Sanitary drainage: constructing, altering, extending, maintaining, repairing, flushing or cleansing any sanitary drain that connects, directly or indirectly, with a sewer.
A person can apply for categories all at once or one at a time, and needs to be licensed in every category they intend to work in. So for work on a sanitary drain, the category that covers it is draining.
Licences, certificates and supervision
NSW issues contractor licences to individuals and to companies or partnerships, qualified supervisor certificates, and tradesperson certificates. The rules on working under supervision are specific:
- A person with a tradesperson certificate must work under the general supervision of someone holding a contractor licence or qualified supervisor certificate, who must also sign off the work.
- A person with no licence, apprentices included, must work under that person’s immediate supervision, which Building Commission NSW takes to mean physically present, with a clear line of sight of the work.
Three tips from the NSW Government
- “Get more than one written quote.”
- “Ask for references and examples of past work.”
- “Don’t pay any money without a written contract.”
Doing plumbing, draining or gasfitting work without a licence or certificate breaches the Home Building Act 1989. As at October 2026, the NSW Government’s page says the fine is $22,000 for an individual or $110,000 for a company.
For hot water work in particular, Pit 04 sets out the temperature rules a licensed plumber is responsible for meeting.