Add or remove GST from any amount.

GST is a tax on most things sold in New Zealand. The rate is 15%. When you are registered, you add 15% to your prices, collect it from your customers, and pass it on to Inland Revenue. You are a collector, not the person paying it. The customer pays. You just handle the paperwork.

It runs both ways. On the GST you charge, you can subtract the GST you paid on your own business costs, such as materials, fuel, tools, and your phone bill. You send Inland Revenue the difference. Some periods you pay, some periods you get a refund. That is normal.

The line is $60,000. You must register for GST once your turnover from a taxable activity was at least $60,000 over the last 12 months, or you expect it to hit $60,000 in the next 12 months. Turnover means your total sales, not your profit. A sole trader on the tools clears that faster than most people expect.

You can also register below $60,000 if you want to. Some people do it to claim GST back on a big startup purchase, or because their trade customers expect a GST invoice. The catch is that once you are in, you file returns whether you feel like it or not, so weigh it up. If you are close to the threshold and unsure, a quick word with an accountant is money well spent.

If your enquiries have dried up and you are wondering whether it is your pricing or something else, that is usually a website problem rather than a tax one. We wrote a plain read on why a site gets traffic but no enquiries if that sounds familiar.

Adding GST is easy. Multiply by 1.15. A $1,000 job becomes $1,150. The $150 is the GST.

Removing GST is where people trip. Say a customer paid you $1,150 and you need to know the GST inside it. The wrong move is to knock off 15%. That gives $977.50, which is wrong. Here is why. The 15% was added to the smaller number, not the bigger one, so 15% of the total is more than the GST actually charged.

The right way is to divide by 1.15. So $1,150 divided by 1.15 is $1,000. That $1,000 is the amount before GST, and the GST portion is the $150 left over. There is a shortcut for the GST portion on its own: multiply the total by 3 and divide by 23. That gives the same $150. Use whichever sticks in your head. The calculator above does it for you either way.

Once you are registered, your invoices need to carry the right information. Inland Revenue now calls this taxable supply information, the term that replaced tax invoice from 1 April 2023. The old label still works on your paperwork, the rules behind it just got a little more flexible.

For a normal job, show your business name and GST number, the date, a description of what you did, and the amount with GST shown. For larger supplies you also show the buyer's details. Keep it clear. A tradie invoice that reads $1,150 including GST with your GST number on it does the job. You do not need fancy software, though it saves time when returns are due.

Two habits save pain later. First, put money aside as it comes in, because the GST you collect is not yours to spend. A separate account for it stops the nasty surprise when the return lands. Second, keep every receipt for business costs, because that is what you claim back. A photo of the docket is enough. Miss the receipt and you miss the claim.

Most small businesses file every two months, which is the standard. Smaller operators can file every six months, and larger ones file monthly. You pick a basis too, usually the payments basis for a small trade, meaning you account for GST when the money actually moves rather than when you send the invoice. Your accountant will point you to the right combination. The main thing is to file on time, every time, because Inland Revenue charges penalties and interest on late returns and that is pure waste.