Provisional Tax Uplift Calculator NZ

This calculator works out your New Zealand provisional tax instalments using the standard uplift method, the approach most self-employed people and small business owners use to spread this year tax bill into instalments rather than one lump sum. You enter your prior year residual income tax, the uplift percentage that applies (commonly 105% if last year return was filed on time, or 110% in some cases), and the number of instalments you pay, usually three. The calculator returns your total provisional tax for the year, the amount due at each instalment, and a running total so you can see the instalments add up through the year. This makes it easy to set money aside ahead of each due date, since dates depend on your balance date, with a 31 March balance date typically falling in August, January and May. The uplift method is simple and gives certainty, but it can mean paying more than needed if profit has dropped, or leaving a top-up bill if profit has risen, and the page explains how this compares with estimating your current-year profit instead. Adjust the figures to model your own situation. This is a planning estimate only, based on general rules and not tax advice, so check your due dates, uplift percentage and obligations with Inland Revenue or your accountant before relying on the figures.

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$18,900.00
total provisional tax for the year (uplift method)
Per instalment$6,300.00
InstalmentAmountRunning total

The standard uplift is commonly 105% of the prior year residual income tax where last year return was filed on time, or 110% based on the year before in some cases. Instalment due dates depend on your balance date, with a 31 March balance date typically having three instalments in August, January and May. Estimate only and general information, not tax advice. Check the current rules with Inland Revenue.

How it works

The standard uplift method takes your residual income tax from last year and multiplies it by the uplift percentage to set this year provisional tax. That total is then split into equal instalments paid through the year. The method gives certainty and is simple, but if your income rises sharply you may still face a top-up, and if it falls you may overpay, which is when estimating can help. The calculator shows the total and each instalment so you can set money aside in good time.

Worked example

With $18,000 of residual income tax last year and a 105% uplift, this year provisional tax is $18,900. Paid in three instalments, that is $6,300 each. Knowing this in advance lets you budget rather than scrambling when each instalment falls due.

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Data sources: the rates and thresholds on this page are maintained against Inland Revenue. Figures are checked twice monthly.