IAS stands for Instalment Activity Statement. Think of it as a gap filler when you don’t have to lodge a BAS for a certain period.

Instalment Activity Statement

The Instalment Activity Statement (IAS) covers PAYG instalments, PAYG withholding and ABN withholding. These three – nothing else. So no GST.

Your IAS comes in, when a particular period is not covered by your BAS. For example, when you report PAYG W on a monthly basis but your GST on a quarterly basis.

PAYG Instalments

The ATO will tell you whether, when and how much you need to pay in PAYG instalments on your so-called instalment income.

Your instalment income includes dividends, interest, profits you made as a sole trader or through a partnership and other income that is not subject to any other withholding, but excluding capital gains. 

PAYG Withholding

For PAYG withholding you are either a small, medium or large withholder depending on your PAYG withholding. 

As a small withholder (less than $25,000 of PAYG W) you report and pay quarterly – through your BAS if you report GST quarterly, otherwise your IAS.

As a medium withholder ($25k to $1m of PAYG W) you report and pay monthly – whether through your BAS or IAS depends on what you do for GST.

Large withholders (more tha $1m) are complicated, so let’s put those aside.

ABN Withholding

If a supplier does not provide an ABN to you for goods and services of more than $75 (excluding GST), you need to withhold the top rate of tax from the payment and report this through your IAS or BAS.


If you are not registered for GST, you don’t have any Business Activity Statements (BAS) to worry about. All your reporting is done through an IAS – either monthly, quarterly or annually.

But if you are registered for GST, then it gets more complicated, especially if your GST and PAYG instalments or withholding are on different reporting cycles.

You might do your BAS quarterly but might be a medium withholder for PAYG Withholding and hence need to report PAYG W on a monthly basis. In that case you do both. You lodge your BAS quarterly, but then lodge an IAS for the months in between.

Does this make sense so far? Just call me if you get stuck. My number is 0407 909 779. I am Heide.



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Disclaimer: numba does not provide specific financial or tax advice in this article. All information on this website is of a general nature only. It might no longer be up to date or correct. You should contact us directly or seek other accredited tax advice when considering whether the information is suitable to your circumstances.

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Last Updated on 16 August 2020