Short answer: without a GST number, you can pay 15% on top of every dollar you spend on Amazon ads, and you never get it back. Amazon bills New Zealand advertisers from companies outside New Zealand, and its tax guide says it adds your country's GST when you have not given a valid GST number. A KDP author can register for GST voluntarily, far below the NZ$60,000 threshold. Once your number is on your Amazon Ads account, the 15% goes. With NZ$1,000 of ads a month, the government keeps NZ$1,800 a year that could stay with you.
For New Zealand KDP authors, Merch on Demand designers and small sellers, from Inland Revenue (IRD) and Amazon Ads' own pages, checked in October 2026. This is information, not tax advice: confirm your case with your accountant.
Work out what you lose with our free calculator
How much you lose each year
New Zealand GST is 15%. Without a GST number, it is a pure cost on your ads:
| Ads per month | GST per month | GST per year |
|---|---|---|
| NZ$300 | NZ$45 | NZ$540 |
| NZ$1,000 | NZ$150 | NZ$1,800 |
| NZ$3,000 | NZ$450 | NZ$5,400 |
Why Amazon charges you 15%
There is no amazon.co.nz, so your ads are billed from abroad. A New Zealand author advertises on amazon.com.au, amazon.com or another marketplace. The Amazon company that bills you depends on that marketplace (Amazon Commercial Services Pty Ltd for amazon.com.au, Amazon Advertising LLC for amazon.com, for example), and none is a New Zealand company.
New Zealand taxes "remote services" bought from abroad. IRD: a non-resident business supplying remote services to New Zealand residents "may be required to register for, collect and return" GST on them. It must treat a New Zealand customer as not registered unless the customer states it is GST-registered or gives a GST number or a New Zealand business number.
Amazon applies that rule. Its tax guide: GST is chargeable when the advertiser "has not provided Amazon with a valid VAT/GST registration number" and "is established in a country that has introduced ESS or remote services rules".
Check the Tax line at the bottom of your Amazon Ads invoice: it shows what you paid.
Can a KDP author register for GST?
Yes. Below NZ$60,000 you are not forced to, but you can. IRD: "You can still register for GST if your turnover from a taxable activity is less than $60,000."
Your KDP royalties are what make it pay:
- What you sell Amazon is a copyright licence. Under the KDP agreement, you grant Amazon a "nonexclusive, irrevocable, right and license to print" and distribute your book. Your royalties are the price of that licence.
- You sell it to Amazon companies outside New Zealand. The KDP agreement pays royalties through "the Amazon party that made the sale (or whose affiliate made the sale)", and none of its parties is a New Zealand company.
- So your royalties are zero-rated. IRD lists as zero-rated "services supplied to non-residents outside New Zealand at the time the service is performed". That is exactly your case: you charge 0% GST on them. IRD's own example points the same way: a copyright fee is zero-rated when the buyer "will be publishing and selling the book overseas".
- Zero-rated sales keep your right to claim. Your royalties are taxable at 0%, so the GST on your ads stays claimable, which IRD lists among the advantages of registering: "you can claim on your expenses relating to your taxable activity".
IRD has never ruled on KDP royalties as such: if you want that in writing before you register, ask it for a binding ruling on your case.
What changes once you are registered
- Register for GST with IRD, in myIR.
- Add your GST number to Amazon Ads. As a KDP author: Administration, Billing, Payment Settings, then the Tax info section.
- Amazon stops adding the 15%. IRD: a foreign supplier does not have to charge GST on remote services to "New Zealand businesses that are already GST registered, and the services are for their business use".
- You have nothing to reverse charge. IRD applies the reverse charge only when your taxable use of the imported service "is less than 95%". Ads for books whose royalties are zero-rated are 100% taxable use.
Unlike in Australia or Canada, there is no New Zealand Amazon company that would keep charging GST: once registered, you simply stop paying it.
What it costs, and when it pays
Registering is not free. IRD lists the disadvantages itself: "you need to add GST to your prices", "you need to file returns regularly", and "you are charged penalties if your returns or payments are late". With sales under NZ$500,000, you can file every six months, so two returns a year.
Say software or a bookkeeper costs you NZ$600 a year (our assumption, not an official figure):
| Ads per month | GST saved per year | Gain after NZ$600 |
|---|---|---|
| NZ$200 | NZ$360 | −NZ$240 |
| NZ$400 | NZ$720 | +NZ$120 |
| NZ$1,000 | NZ$1,800 | +NZ$1,200 |
| NZ$3,000 | NZ$5,400 | +NZ$4,800 |
Registering pays from about NZ$335 of ads a month. Below that, it costs more than it saves.
The limits you need to know
Nothing is refunded for the past. Count on the savings from your registration date on. Amazon refunds tax only with proof that "registration was active during the billing period".
If you sell to New Zealanders yourself, you add GST to those sales. Books you sell at a market, from your website or to a local shop then carry 15% GST. For an author whose income is KDP royalties, this rarely bites. For a seller of goods to New Zealand consumers, it can wipe out the gain. Prices unchanged:
| Per month | Not registered | Registered |
|---|---|---|
| Sales | NZ$5,000 | NZ$5,000, of which NZ$652 GST to pay |
| Ads | NZ$1,150 (with GST) | NZ$1,000 (no GST) |
| What is left | NZ$3,850 | NZ$3,348 |
That seller loses about NZ$500 a month by registering. Registering pays when your income carries no GST, which is the case of KDP royalties.
Merch on Demand: the same reasoning holds only if your Merch royalties, like KDP royalties, come from an Amazon company outside New Zealand. Check your Merch agreement with your accountant before you count on it.
Frequently asked questions
Do I charge GST on my KDP royalties once registered?
No. They are services supplied to non-resident Amazon companies outside New Zealand, which IRD lists as zero-rated: 0%.
Must I register once my turnover reaches NZ$60,000?
Yes. IRD: you must register if your turnover "was at least $60,000 in the last 12 months", or you expect it to be in the next 12 months.
Will Amazon refund the GST I already paid?
Only for billing periods when your GST registration was already active. Ads billed before your registration date are not covered.
I spend NZ$150 a month on ads. Should I register?
Probably not for this reason alone: you would save NZ$270 a year, less than a typical bookkeeping bill. Run your own figures in the calculator.
Before you decide
Work out what you lose with our free calculator: enter your monthly ad spend, see the GST you pay each year and what registering would change. Then take the figure to your accountant.
Spending less on ads for the same sales helps too: see how much Sponsored Products ads cost and whether KDP authors can run Sponsored Brands ads. Authors elsewhere: Australia, Singapore, Canada.
Sources
- Registering for GST, Inland Revenue
- Registering for GST voluntarily, Inland Revenue
- Zero-rated supplies, Inland Revenue
- Supplying remote services into New Zealand, Inland Revenue
- Special supplies (reverse charge, 95% rule), Inland Revenue
- Which GST accounting basis and filing frequency should I use, Inland Revenue
- Amazon Advertising Agreement ("Amazon Contracting Party", "Elected Country"), Amazon Ads
- Understanding taxes and regulatory fees on your advertising invoice, Amazon Ads
- Register your Tax ID and Tax refunds, Amazon Ads help
- KDP Terms and Conditions (the Amazon parties, royalties), Amazon KDP
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