Tax Facts

Provisional Tax

Provisional Tax is not a separate tax but a way of paying your income tax as the income is received through the year. You pay instalments of income tax during the year, based on what you expect your tax bill to be. The amount of provisional tax you pay is then deducted from your tax bill at the end of the year.

If your residual income tax is $2,500 or more you will have to pay provisional tax for the following year. Residual income tax is basically the tax to pay after subtracting any rebates you are eligible for and any tax credits (excluding provisional tax). Residual income tax is clearly labelled in the tax calculation in your tax return.

There are three options for working out your provisional tax: standard, estimation, and ratio (available from 2008-2009 year onwards).

Standard option

The IRD automatically charges provisional tax using the standard option unless you choose the estimation or ratio options. Under this option:

• Your provisional tax payable is your previous year's residual income tax plus 5%
• Changes in tax rates may have an effect on the calculation of your provisional tax

Estimation option

The other way to work out your provisional tax is to estimate what your residual income tax will be. When working out the tax, keep the following points in mind:

• To get the right tax rate -
• Add up all your estimated income
• Work out the tax on the total
• Subtract any tax credits (like PAYE)
• Using the estimation option, if your estimated residual income tax is lower than your actual residual income tax for that year, you may be liable for interest on the underpaid amount
• You can estimate your provisional tax as many times as necessary up until your last instalment date. Each estimate must be fair and reasonable

Ratio option (for 2008-2009 onwards)

From the start of your 2008-2009 income year you can base your provisional tax instalments on a percentage of your GST taxable supplies. You will be able to use the ratio option if:

• You’ve been in business and GST-registered for all of the previous tax year, and the tax year prior to that
• Your residual income tax for the previous year is greater than $2,500 and up to $150,000
• You file your GST returns every month or every two months
• The business you’re operating is not a partnership
• Your ratio percentage that IRD calculates for you is between 0% and 100%

The ratio will be calculated by applying the following rule:

Ratio Percentage = Residual Income Tax from previous year/GST Taxable Supplies from previous year x 100/1

Due dates

The due date and amount of instalments you need to make for payment of your provisional tax each year depends on your balance date, which of the above options you use and how often you pay GST (if registered).  

If you have a 31 March balance date and  use the standard or estimation option or are also GST Registered on a 1 or 2 monthly basis, the provisional tax payments are due on:

Interest

In some circumstances you may be charged interest if the provisional tax you paid is less than your residual income tax.  If the provisional tax you pay is more than your residual income tax, the IRD may pay you interest on the difference.

For futher information on provisional tax, due dates and changes made by IRD refer to the IRD Website.