GST can be a small detail on a quote, but for homeowners it can make a big difference to the final bill. In New Zealand, most trade work is priced either exclusive of GST or inclusive of GST, and knowing which one you are looking at helps you compare quotes properly and avoid surprises at invoice time.
What GST means for home trade work
GST is New Zealand’s goods and services tax, currently 15%. Most established tradies and trade businesses are GST-registered once their taxable turnover passes the registration threshold, so they must charge GST on taxable supplies and show it correctly on their invoices.
For homeowners, the main point is simple: if a tradie is GST-registered, the amount you pay will usually include GST, even if the quote you first see does not.
When GST applies
GST generally applies to most labour and materials used in home improvement work, including:
• Building and renovations
• Plumbing and drainage work
• Electrical work
• Painting and decorating
• Roofing and guttering
• Landscaping and fencing
• Heat pump installation and other many standard home services
Some items can be more complex, especially where mixed supplies are involved, but for most residential jobs the full job price will attract GST if the business is registered.
Reading quotes: inclusive vs exclusive of GST
This is where many homeowners get caught out. A quote can be written in two common ways: exclusive of GST or inclusive of GST.
Exclusive of GST
If a quote says $10,000 + GST, the final amount you pay is $11,500. The GST is added on top of the quoted price.
This format is common in trade and business-to-business quoting because it shows the base job price before tax. It is perfectly normal, but it is important to check the fine print so you know the true total.
Inclusive of GST
If a quote says $11,500 including GST, that is the full amount you should expect to pay, assuming the scope of work does not change.
For homeowners, inclusive pricing is often easier to compare because it shows the real out-of-pocket cost straight away.
How to compare quotes fairly
Do not compare one quote including GST with another quote excluding GST. That is one of the easiest ways to choose the wrong contractor by mistake.
To compare properly:
• Check whether each quote is GST inclusive or exclusive
• Convert every quote to the same basis before comparing
• Confirm whether materials, labour, waste removal, and travel are included
• Ask whether any subcontractor costs or permit-related costs are extra
• Make sure the quote clearly states what work is covered and what is not
If a quote seems unusually cheap, GST might be the reason, or it may simply be missing important items.
What should be on a proper invoice
A GST invoice is more than just a bill. It should make it clear who supplied the work, what was done, and how much GST was charged.
For GST-registered tradespeople, a proper invoice generally includes:
• The business name and GST number
• The date of the invoice
• A description of the work carried out
• The amount charged before GST
• The GST amount separately shown
• The total amount payable
• Payment terms and due date
If the invoice is for a lower value, it may be a simplified GST invoice, but it should still clearly show the key tax information.
Why this matters to homeowners
A clear invoice helps you:
• Check that the final charge matches the quote
• See exactly what GST was added
• Keep records for insurance claims or warranty issues
• Resolve disputes if extra work was added later
If the invoice looks vague, ask for a corrected version before paying.
Typical trade costs and what GST changes
GST does not change the underlying cost of the work, but it does change the amount you actually pay. For larger jobs, that 15% can be significant.
Here are indicative NZ price ranges for common residential trade work before and after GST may be applied, depending on how the quote is presented:
• Minor plumbing repair: $180–$450 excl GST, or $207–$518 incl GST
• Basic electrical fault-finding or small repair: $150–$400 excl GST, or $173–$460 incl GST
• Interior painting for a small room: $500–$1,200 excl GST, or $575–$1,380 incl GST
• Heat pump installation: $2,500–$5,500 excl GST, or $2,875–$6,325 incl GST
• Bathroom renovation trade labour: $8,000–$25,000+ excl GST, or $9,200–$28,750+ incl GST
• Roofing repairs: $500–$3,000 excl GST, or $575–$3,450 incl GST
These are only broad guides. Access, location, materials, consent requirements, and the condition of the home can all affect the final price.
GST rules homeowners should watch for
There are a few common situations where GST can be confusing.
The tradie may not be GST-registered
Some very small businesses are not GST-registered. If that is the case, they should not charge GST.
That means a quote for $1,000 from a non-registered contractor is usually just $1,000 total, not $1,150. It is worth checking because a lower base price from a non-registered business can sometimes look similar to a GST-inclusive price from a registered one.
Deposits and progress payments
For larger jobs, tradies may ask for a deposit or staged payments. GST is usually accounted for as those taxable supplies are invoiced, so make sure each payment stage is documented clearly.
If you are paying a deposit, ask whether the deposit amount includes GST or whether it will be added separately.
Variations and extra work
Any change to the scope of work can affect the price, and GST will usually apply to the extra charge as well.
For example, if a builder finds rotten framing, or an electrician discovers unsafe wiring that must be upgraded, the extra work should be priced clearly before it begins wherever practical.
Practical tips before you accept a quote
A good quote should leave no doubt about the total cost.
Before you sign, check the following:
• Is the quote marked GST inclusive or exclusive?
• Does it list labour, materials, and disbursements separately?
• Are council consents, waste disposal, scaffolding, or call-out fees included?
• Is the payment schedule clear?
• Are allowances and provisional sums explained?
• Does the quote state that any variations will be charged at an agreed rate?
If anything is unclear, ask for the quote to be rewritten in plain language. A reputable tradie will usually be happy to explain the numbers.
The bottom line for homeowners
GST is not something to fear, but it is something to check carefully. The main takeaway is to always confirm whether a quote is inclusive or exclusive of GST, and make sure the invoice matches what you agreed to.
For small jobs, GST might only add a modest amount. For a major renovation or extension, it can add thousands of dollars. Taking a few minutes to check the GST wording upfront can save you from budget blowouts and awkward disputes later.
If you are comparing tradies in New Zealand, ask each one to quote on the same GST basis, confirm what is included, and keep every invoice for your records. That way, you can focus on the quality of the work rather than surprises on the final bill.