How to Choose a Plumber in New Zealand

How to Choose a Plumber in New Zealand

The thing most homeowners get wrong about plumbers is the word "registered". In New Zealand, being registered with the Plumbers, Gasfitters and Drainlayers Board is not the same as being allowed to do the work. Registration proves knowledge. A licence is what authorises someone to actually carry out restricted sanitary plumbing, gasfitting or drainlaying — and every licence expires on 31 March each year.

There is a third layer on top, and it changed in 2026. Only certifying plumbers and drainlayers — the highest registration class — can apply for a Board endorsement to self-certify eligible work without a council inspection. That endorsement sits on the public register, so you can check it before you book anyone.

This guide is about choosing a person, not comparing prices. Sanitary plumbing is our focus here; we cover drainlaying and gasfitting separately. The plumbing job is usually the cheap part of a repair. The expensive part is making good the wall, the tiles or the floor afterwards — so the questions below are mostly about who is responsible for what.

How We Researched This Guide

We worked from the Plumbers, Gasfitters and Drainlayers Board's own published material on registration and licence classes, its guidance on the self-certification scheme, and Building Performance's overview of the same scheme. The rules on restricted work and annual licensing are set out in full on the Board's site, and the underlying consenting framework sits in the Building Act 2004 on legislation.govt.nz.

Two things surprised us. The first is how many people ask "are you a plumber?" and get a true answer that is not the answer they need — the real question is which class, and whether the licence is current. The second is the 31 March expiry, which applies across the board. We also had to be careful with the 2026 self-certification change: a building consent is still required where one would normally be needed. The scheme changes who signs the work off, not whether you need consent.

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The Quick Summary (60-Second Version)

If you read nothing else, read this.

• Ask for the registration number, the registration class and the expiry date of the practising licence — then check all three on the Board's public register.
• Registration alone is not authorisation. A restricted or plumber/gasfitter/drainlayer licence holder must have an active certifying supervisor listed.
• All licences and authorisations expire on 31 March each year, and re-licensing requires continuous professional development.
• If the work needs a building consent, ask whether the plumber is a certifying plumber with a Board self-certification endorsement.
• Ask who is responsible for reinstating the wall, tiles or floor. That is usually the expensive part of the job.
• Get the scope, exclusions, GST basis and warranty in writing before anyone starts.

The Three Registration Classes, and Why They Decide Everything

The Board registers people in three classes: restricted, plumber/gasfitter/drainlayer, and certifying. Registration represents proven knowledge and competence, and it happens once, when someone qualifies. A licence is different. The licence is the authorisation to carry out restricted work, and the Board issues it annually.

That distinction has a practical consequence. A restricted licence holder and a plumber/gasfitter/drainlayer licence holder must each have an active certifying licence holder in the relevant trade listed as their supervisor. They do not need that person standing next to them — direct-presence supervision is not required — but the supervisor remains responsible for the work. So "who is your certifying supervisor?" is a fair question, and a plumber who cannot answer it is a problem.

What the certifying class unlocks

The certifying class is the top of the ladder, and it is the class that matters for consent work. A certifying plumber is the person who can verify the work for consenting purposes. Since 7 September 2026, only a currently licensed certifying plumber or drainlayer holding a Board self-certification endorsement can self-certify eligible work.

The scheme is voluntary — certifying practitioners choose whether to apply — and it applies to eligible plumbing and drainlaying work in residential, commercial and industrial buildings up to three storeys, excluding apartment blocks. Regulations define which types of work are self-certifiable.

What self-certification does not change

A building consent is still required where one would normally be needed. Councils still assess proposed work for Building Code compliance at the consent stage, all work must still comply with the Building Code, and plumbers and drainlayers must still be licensed and meet professional and disciplinary requirements.

The three questions that cover any plumbing job

What Actually Separates One Plumber From Another

Once you have confirmed registration, the class and the current licence, the remaining differences are about how the person works. The best signal is whether they ask about your water pressure and the age of the pipework before quoting. A plumber who quotes without looking in the roof or under the floor is guessing, and you will pay for the guess.

Watch for whether they will open the wall or the floor to find the actual problem instead of working from what the last person said. Watch whether they test their own work in front of you and tell you what they tested. And watch whether they tell you what they found that is not part of the job, then leave the decision with you rather than starting extra work unasked.

Questions worth asking before you agree to anything

Does this work need a building consent? What certificate will I get at the end? Are you licensed for gasfitting as well, if the work touches gas? What will you do if you find something else behind the wall? What is the warranty on the parts and on the labour? Do you hold public liability insurance, and do you hold the civil liability insurance required for self-certification?

Then the one people forget: who is making good? Plumbing costs break into the call-out, the labour rate, the fittings and materials, and any consent or certification costs. The drivers are accessibility, the age and material of the existing pipework, whether a consent is triggered, and whether it is an emergency or a scheduled repair. A leaking tap and a leaking pipe under a slab are entirely different jobs.

Getting the quote right

Ask for a written quote rather than an estimate. A quote is a fixed price for defined work; an estimate is an approximation and can legitimately be exceeded. Make sure the quote says what is excluded, who supplies materials, whether the price includes GST, and what happens if extra work is discovered.

Questions You Might Have

Do I need a building consent to replace a toilet or a tap?

Usually not for a straight like-for-like replacement, but consent rules turn on whether the work creates a new sanitary fixture or alters drainage. The honest answer is that it depends on the specific job, so ask the plumber directly and confirm the position with your council before work starts. A plumber who cannot tell you whether consent is triggered is not the right person for consent work.

What is the difference between a certifying plumber and a regular plumber?

Certifying is the highest of the three registration classes — the others are restricted, and plumber/gasfitter/drainlayer. A certifying plumber can supervise others and can verify work for consenting purposes. Only a certifying plumber or drainlayer with a Board self-certification endorsement can self-certify eligible work without a council inspection.

How do I check a plumber's licence?

The Board operates a public register you can search by name or part of a name, by town, city or postcode, by company name, or by class of registration. It shows the person's registration and licence history, any conditions on their licence, whether they supervise anyone or are supervised, and any disciplinary decisions. Check the registration and the expiry date, not just the name.

Can I supply my own tap or shower and have the plumber fit it?

Some will, some will not, and the reason is usually liability rather than stubbornness — if a customer-supplied fitting fails, it is hard to establish whether the fault was the product or the installation. Ask before you buy. If they agree, get it in writing that the warranty covers their labour but not the fitting itself.

What if the work is faulty?

Under the Consumer Guarantees Act 1993, services must be carried out with reasonable care and skill. Give the plumber the chance to fix it first, and put the request in writing. If they refuse or do not succeed within a reasonable time, you can have it remedied elsewhere and recover reasonable costs, or cancel the contract. The Disputes Tribunal can hear claims up to $60,000.

What Matters Most

The plumbing trade is one of the few in New Zealand where you can verify almost everything that matters in about ninety seconds. The register is free, public and searchable, and it shows the class, the licence history, any conditions and any disciplinary decisions. Use it. Then ask the two questions that the register cannot answer: is the licence current, and who is the certifying supervisor.

After that, the decision is mostly about scope and making good. The cheapest quote is frequently the one with the narrowest scope, and the plumbing labour is rarely the biggest line on the invoice once a wall has been opened. Ask who reinstates it. Ask what happens if something else turns up. Ask what certificate you will receive at the end.

Do that, and you have done more due diligence than most homeowners ever do.