Work out provisional tax using the ratio option

All Income tax dates

We work out your ratio percentage

We'll divide your residual income tax (RIT) for the last tax year by your total GST-taxable supplies for the same year.

If last year's figures aren't available, we'll use the residual income tax and total GST-taxable figures from the previous year.

We'll let you know what it is before your first provisional tax payment due date.

Multiply the ratio percentage by your GST-taxable supplies for the previous 2 months.

You’ll make your provisional tax payments along with your GST returns. You can make payment or request a ratio percentage in myIR.

Other ways to do this

File a GST and provisional tax return - GST103B