I am a two instalment payer for GST instalment purposes. What is my GST instalment amount based on?
The GST instalment amount printed at box G21 of your activity statement is generally based on the actual GST net amounts you reported in your activity statements and/or Annual GST return (PDF, 110KB) for the last income year. It is also adjusted to reflect expected growth in income. The adjustment is made in line with movement in Australia’s gross domestic product (GDP). The source of the GDP data is the Australian Bureau of Statistics. How the GST instalment amount is calculated depends on the option you used to report and pay GST in the last income year. If you previously calculated your actual GST net amounts yourself, your current GST instalment amount calculated by the Tax Office is the average of your net GST amounts for the last income year, adjusted by GDP. If you previously used GST instalment amounts calculated by the Tax Office (or varied amounts), your current instalment amount is calculated from your July — September 2001 and October — December 2001 activity statements, an
