Provisional tax instalments, standard option.
Total provisional tax
—
Each of 3 instalments
—
What provisional tax is paying for
Provisional tax catches everyone whose income arrives without PAYE already taken out: sole traders, landlords, contractors, and anyone whose residual income tax for the year topped $5,000. Inland Revenue does not want a full year of tax landing as one lump sum the following February, so it asks you to pay this year’s tax in instalments as you earn. Think of it as PAYE for the self-employed, just paid in larger, less frequent chunks. The catch is that you are paying tax on income you have not finished earning yet, so the system needs a sensible way to guess the figure. That is where the standard uplift method comes in.
Why last year plus 5 percent
The standard option starts from a number IRD already knows: your residual income tax from the year just gone. That is the tax that was left owing after credits such as PAYE and withholding were applied. It then uplifts that figure by 5 percent on the assumption your business grew a little, and splits the result into three instalments. The logic is that if you pay the uplifted prior-year figure on time, IRD will not charge use-of-money interest even if your actual income turns out higher. It is a safe-harbour deal: predictable payments in exchange for protection from interest.
Working an $18,000 residual tax bill through the year
Suppose last year’s residual income tax was $18,000. The tool uplifts it by 5 percent to $18,900, then divides by three to give instalments of $6,300 each, due in August, January, and May for a standard March balance date. Here is the breakdown.
| Step | Amount |
|---|---|
| Last year residual income tax | $18,000 |
| Uplift at 5% | $900 |
| Total provisional tax | $18,900 |
| Instalment 1 (28 August) | $6,300 |
| Instalment 2 (15 January) | $6,300 |
| Instalment 3 (7 May) | $6,300 |
When the standard option is the wrong choice
The uplift method assumes your income held up or grew. If you know this year will be leaner, perhaps you lost a major client or took maternity leave, paying the uplifted figure ties up cash you cannot spare. The alternative is the estimation option, where you tell IRD your own forecast and pay tax on that. The trade-off is real: if you estimate too low and the actual bill comes in higher, IRD charges use-of-money interest on the shortfall from the relevant instalment dates, and that interest rate is not gentle. My rule of thumb for clients is to use the standard uplift unless you are confident income will drop by more than 10 to 15 percent, in which case a careful estimate saves cash without much interest risk. If your residual tax was under $60,000, paying through tax pooling can also smooth timing and reduce interest exposure.
Do I still file a tax return if I pay provisional tax?
Yes. Provisional tax is only a prepayment. At year end you file your return, your actual residual income tax is calculated, and the provisional instalments you paid are credited against it. If you overpaid you get a refund; if you underpaid you settle the difference by the terminal tax date, usually 7 February the following year, or 7 April if you have a tax agent.
What if this is my first year in business?
In your very first year there is no prior residual income tax to uplift, so you are generally not required to pay provisional tax during that year. The first year’s tax falls due as terminal tax instead. Many new operators voluntarily set money aside or make voluntary payments anyway, because the following year you can face both the prior year’s terminal tax and a full set of provisional instalments at once, which is a common cash-flow shock.