How we calculate

GST is charged at a single flat rate on most goods and services supplied in NZ.

To find the GST already inside a GST-inclusive amount, multiply by 3 and divide by 23.

You must register for GST once your turnover reaches the threshold in any 12-month period (past or expected).

GST returns and payments are due by the 28th of the month after the taxable period ends — with two exceptions: a period ending 31 March is due 7 May, and a period ending 30 November is due 15 January.

There are three ways to account for GST. Payments basis: account when money actually moves. Invoice basis: account on the earlier of the invoice date or the payment date. Hybrid basis: invoice basis for sales/income, payments basis for expenses/purchases.

Exported goods and services and sales to overseas customers are typically zero-rated, so no NZ GST applies and no NZ GST input is claimed on overseas-charged supplies.

GST cannot be charged on rent for a residential dwelling, and the landlord cannot claim GST on dwelling expenses. Financial services such as interest are also exempt.

Individuals (including sole traders) are taxed on a sliding scale of marginal brackets. These five bands apply from the 2025–26 income year (1 April 2025) onward, and therefore to FY2027.

Companies pay a single flat income tax rate on net profit.

You become a provisional taxpayer when your prior-year residual income tax (RIT) was more than $5,000. In your first year you are not yet a provisional taxpayer — you pay terminal tax, then become provisional the next year if that RIT was over $5,000. Under the standard option, provisional tax is the prior-year RIT plus 5%.

Provisional tax is paid in three equal instalments across the year for a 31 March balance date.

Business entertainment with a significant private element (e.g. meals, food and drink, corporate boxes, social events) is half deductible. You claim GST on the full amount at the time, then make a once-a-year GST adjustment to return GST on the non-deductible half.

When you use your home for business, you apportion the cost by your own actual business-use percentage. IRD has no single fixed home-office percentage — the figure is set by you, not by IRD.