Understanding BAS and IAS¶

You may have heard the terms BAS and IAS. They sound similar, and both are kinds of activity statement you send to the Australian Taxation Office (ATO). The difference is simple, and it comes down to one thing — GST.

A BAS is a Business Activity Statement. It includes GST, and it usually reports other obligations too. An IAS is an Instalment Activity Statement. It has no GST on it at all — it reports other obligations on their own.

In one line

A BAS includes GST and usually more. An IAS has no GST — it reports obligations like PAYG on their own.

Why this matters¶

Knowing which statement you have tells you what the ATO is asking for. If you see a BAS, GST is part of it. If you see an IAS, GST is not — so you are only dealing with things like your pay as you go amounts. Reading the right statement the right way helps you fill it in correctly and avoid confusion.

What you will learn¶

What a BAS is and what it covers
What an IAS is and how it differs from a BAS
When you would use each one

Understanding the concept¶

GST stands for goods and services tax. Businesses registered for GST report it to the ATO on an activity statement.

A BAS — a Business Activity Statement — is the statement used when GST is one of your obligations. On the same BAS, the ATO usually also collects other amounts. Two common ones are PAYG withholding (amounts you have taken out of your employees' pay) and PAYG instalments (regular pre-payments towards your own income tax). PAYG stands for pay as you go. So a BAS often brings GST and your PAYG amounts together on one form.

An IAS — an Instalment Activity Statement — is the statement used when there is no GST to report. It covers obligations like PAYG on their own.

You would use an IAS in situations such as these:

Your business is not registered for GST, but you still have a PAYG obligation — for example, PAYG instalments towards your income tax.
You report GST quarterly, but you need to report PAYG withholding in a month that falls between your quarterly statements. In that in-between month, the ATO uses an IAS because there is no GST due that month.

For accountants & bookkeepers

The ATO describes the IAS as the form for taxpayers who have a PAYG obligation but are not registered for GST — for example, individuals and partners reporting PAYG instalments. It is also used by GST-quarterly reporters who withhold and must report PAYG withholding monthly, so the withholding is reported on an IAS in the two non-BAS months of each quarter. Where GST or PAYG instalments are paid by the ATO-advised amount, the ATO may instead issue an instalment notice rather than a statement to complete.

Example¶

Priya runs a small graphic-design business on her own. She is registered for GST and has no employees. Each quarter the ATO sends her a BAS, because GST is one of her obligations — and her PAYG instalment sits on the same form.

Jordan runs a small consulting business that is not registered for GST, because turnover is under the registration threshold. Jordan still pays PAYG instalments towards income tax. Because there is no GST to report, the ATO sends Jordan an IAS instead of a BAS.

Common mistakes¶

Thinking a BAS and an IAS are the same form — the key difference is whether GST is on it.
Expecting GST on an IAS — an IAS never has GST.
Assuming everyone gets a BAS — a business not registered for GST may receive an IAS.

How this works in myaccountant¶

In the app — myaccountant prepares your activity statement from the data already in your books, whether that is a BAS or an IAS. It fills in the amounts for you, shows you the due date, and lets you lodge the statement to the ATO when you are ready.

Key points¶

A BAS is a Business Activity Statement — it includes GST.
A BAS usually reports other obligations too, such as PAYG.
An IAS is an Instalment Activity Statement — it has no GST.
An IAS reports obligations like PAYG on their own.
A business not registered for GST may receive an IAS.
The ATO decides which statement you get and sends it to you.

Learn next¶

General information only — not tax, super or financial advice.

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