Checking a plumber’s licence in NSW

Four kinds of licence

Building Commission NSW issues different licences depending on whether a person wants to contract to do the work, supervise it, do it, or some mix of the three. The four types are below. Each can be issued for one, three or five years, except the provisional tradesperson certificate, which is issued for three years and cannot be renewed.

1. 1Contractor licence or qualified supervisor certificate
2. 2Tradesperson certificate
3. 3No licence, including apprentices
4. 4General supervision, and sign-off of the work
5. 5Immediate supervision, from the contractor licence or qualified supervisor holder

Immediate supervision is the closer of the two. Building Commission NSW says it means the supervisor is always physically present with a clear line of sight of the work, ready to give specific instructions, directly overseeing and reviewing the work, and making sure the finished work complies.

A licence covers named kinds of work

Holding a licence is half the question. The other half is whether it covers the job in front of you, because a person must be licensed in every category they intend to work in, or work under the supervision of someone who is. The categories include:

• Plumbing: water plumbing, sewerage and sanitary work. It does not include draining or roof plumbing.
• Water plumbing on its own, and narrower water plumbing categories for fire protection systems, fire sprinkler systems and urban irrigation.
• Draining: work on any sanitary drain that connects, directly or indirectly, with a sewer, including its maintenance, repair, flushing and cleansing.
• Gasfitting, LP gasfitting and advanced LP gasfitting.

So a person clearing or repairing the sanitary drain under your yard is doing draining work, and their licence should say so.

How to check, step by step

1. Ask for the numberAsk the contractor for their licence number before you hire. Building Commission NSW says: “You should only deal with a properly licensed contractor.”
2. Look it up on Verify NSWSearch the Verify NSW licence register by name or licence number to make sure the licence is valid.
3. Read what the register showsThe public register lists the holder’s name, suburb, year of birth, licence type and validity, any other home building licences they hold, and their compliance history. It is published under section 120 of the Home Building Act 1989.
4. Match the category to the jobCheck that the licence covers the kind of work you need, from the list above.
5. Ask who will superviseA contractor on a large job may bring in a supervisor to manage it. Building Commission NSW says: “Make sure the supervisor has: enough experience in the type of work you want done and a current Supervisor Certificate from Building Commission NSW and their contractor’s licence is properly approved.”

Why it matters

Doing plumbing, draining or gasfitting work without a licence or certificate is a breach of the Home Building Act 1989. As at October 2026, Building Commission NSW lists fines of $22,000 for an individual and $110,000 for a company for unlicensed work, up to $1,500 per breach for not supervising, and up to $1,100 per breach for working unsupervised.

For larger jobs, two more rules from the same regulator: a written contract is required when labour and materials cost more than $5,000, and Home Building Compensation Fund insurance is required for projects over $20,000, before the contractor starts work or takes any payment.

Licences from other states

Plumbing, draining and gasfitting is included in the NSW Automatic Mutual Recognition scheme, and Building Commission NSW points interstate and New Zealand licence holders to its pages on working interstate. If someone tells you they are licensed elsewhere, ask how that applies in NSW and check the register all the same.