GST and Invoicing for NZ Tradies: A Simple Guide (2026)

GST trips up more Kiwi tradies than almost anything else in the business. Do you have to register? Do your prices include it or not? What has to be on an invoice so it's actually valid? Get it wrong and you can end up underpricing every job, or scrambling at return time.

This is a plain-English guide to GST and invoicing for New Zealand tradies. It's general information to help you understand how it works — not tax advice. For your own situation, check with your accountant or Inland Revenue (IRD).

What GST is

GST (Goods and Services Tax) is a flat 15% tax added to most goods and services sold in New Zealand. If you're registered, you collect it on top of your prices, hand it to IRD when you file a return, and claim back the GST you paid on your own business expenses. You're effectively collecting it on IRD's behalf — it was never your money to keep.

Do you have to register for GST?

You must register for GST if your turnover is over $60,000 in any 12-month period — either the last 12 months, or the next 12 months you reasonably expect. "Turnover" is your total sales, not your profit.

If you're under $60,000 you can still register voluntarily. That can be worth it if you're buying a lot of tools, materials or a work vehicle, because you can claim the GST back on those purchases. The trade-off is more paperwork and having to add 15% to your prices, which matters if a lot of your customers are homeowners who can't claim it back.

GST-inclusive vs GST-exclusive pricing

This is where a lot of quotes go wrong. Once you're registered, you need to be crystal clear whether a price includes GST or not:

• GST-exclusive — the price before GST. A $1,000 + GST job is $1,150 to the customer.
• GST-inclusive — the final price the customer pays. A $1,150 inclusive job contains about $150 of GST.

To find the GST inside a GST-inclusive price, divide by 23 and multiply by 3 (or just divide the total by 1.15 to get the pre-GST amount). Homeowners usually want to see the final, GST-inclusive figure. Commercial clients often work in GST-exclusive numbers. Whatever you do, state it clearly on the quote so there's no nasty surprise on the invoice.

What a valid tax invoice needs

When you're GST-registered, your invoices need to carry enough information for your customer to claim the GST back. For most jobs, that means showing:

• Your business name and GST number.
• The date of the invoice.
• A clear description of the work and materials supplied.
• The amount charged, and either the GST amount or a statement that GST is included (for example, "All prices include GST").

Keep the numbering sequential and unique so your records are clean and easy to reconcile at return time. If a customer asks for the details to claim GST, you generally need to provide them within 28 days.

Filing your GST returns

When you register, you choose how often you file — commonly monthly, two-monthly or six-monthly, depending on your turnover and how you like to manage cashflow. Each return, you add up the GST you collected on sales, subtract the GST you paid on business expenses, and pay IRD the difference (or get a refund if you spent more than you earned that period).

The tradies who find GST painless all do the same thing: they keep their invoicing and expenses tidy as they go, instead of drowning in a shoebox of receipts the night before a return is due.

Common GST mistakes to avoid

• Spending the GST you collected. It isn't yours — set it aside so return time isn't a shock.
• Forgetting to add GST to a quote and having to wear the 15% yourself.
• Missing your registration threshold. Once you're heading past $60,000, register — don't wait for a letter.
• Sloppy invoices that don't show your GST number, so commercial customers can't claim and chase you to redo them.
• No records. Keep every invoice and expense so you can back up what you filed.

Make GST and invoicing the easy part

Most GST stress comes from messy admin, not the tax itself. TradieJet builds GST into your quotes and invoices automatically at the NZ rate, gives every document a sequential number and your GST details, lets customers pay online, and syncs straight to Xero or MYOB so your GST returns line up without the shoebox.

See how TradieJet works, find your trade, or start a free trial and take the pain out of GST and invoicing.