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BAS and GST: how to report GST on your activity statement

What the ATO asks you to report for GST on your business activity statement, how often, and when it is due, with a worked example and a checklist. General information, not advice.

What a BAS is

If your business is registered for GST, you need to lodge a business activity statement (BAS). You use it to report and pay the GST you collected and to claim GST credits for the GST in your business purchases. The same form can also cover pay as you go (PAYG) instalments, PAYG withholding and other taxes.

Each BAS is personalised to your business, so report on the form the ATO gives you. You can lodge online, through a registered tax or BAS agent, or by mail. If you have nothing to report for a period, you still lodge a “nil” BAS by the due date.

Not registered yet? The Australia GST calculator page explains who has to register.

How often you report GST

Your GST reporting and payment cycle depends on your GST turnover:

Some quarterly reporters can instead pay a quarterly GST instalment that the ATO works out and report their actual GST once a year on an annual GST return. Eligibility includes a business with an aggregated turnover of less than $10,000,000. You have to contact the ATO to use it.

The GST labels you fill in

If your GST turnover is less than $10,000,000, you use the Simpler BAS reporting method (unless you are on GST instalments). For GST you report only three labels:

Under Simpler BAS you do not report G2 Export sales, G3 Other GST-free sales, G10 Capital purchases or G11 Non-capital purchases.

If your GST turnover is $10,000,000 or more, you must use the full reporting method and also report G2, G3, G10 and G11. You can choose full reporting below that if your aggregated turnover is over $10,000,000, or if input-taxed supplies are your main business activity.

G1 includes your taxable, GST-free and input-taxed sales. You can show G1 including or excluding GST if you use the accounts method, and you mark which on the form. On the BAS itself you round down to whole dollars, leave out cents, and do not use negative figures or symbols such as $.

Cash or accruals

There are two ways to account for GST: a cash basis and a non-cash (accruals) basis. The one you use decides which BAS a sale or purchase goes on.

You can use the cash basis if you are a small business entity with an aggregated turnover of less than $10,000,000, if you are not carrying on a business and your enterprise's GST turnover is $2,000,000 or less, if you account for income tax on a cash basis, or if you run a kind of enterprise the ATO has agreed can use it. Otherwise you can ask the ATO for permission.

Either way, you need a tax invoice before you claim a GST credit, except for purchases of $82.50 or less, and you have 4 years to claim a credit.

Worked example: what you pay or get back

If the GST you collect is more than the GST credits you claim, you send the difference to the ATO with your BAS. If your credits are larger, you may get a refund. When a sale or purchase includes GST at 10%, the GST is one eleventh of the GST-inclusive amount.

Paying. In a quarter you make taxable sales of $33,000 including GST and buy $5,500 of business supplies including GST. GST on sales (1A) is $3,000. GST on purchases (1B) is $500. You pay the difference: $3,000 − $500 = $2,500.

A refund. In another quarter you make taxable sales of $4,400 including GST and buy equipment for $13,200 including GST. 1A is $400 and 1B is $1,200. Your credits are larger, so the GST part of the BAS is a refund of $1,200 − $400 = $800.

Under Simpler BAS, G1 in the first quarter would be $33,000 including GST or $30,000 excluding it, depending on how you report. Other amounts on your BAS, such as PAYG, change the final total. The Australia GST calculator finds the GST inside any total.

When to lodge and pay

The due date for lodging and paying is shown on your BAS. The ATO's table for quarterly BAS:

QuarterDue date
1. July, August and September28 October
2. October, November and December28 February
3. January, February and March28 April
4. April, May and June28 July

If you lodge or pay late

A general interest charge (GIC) applies to any amount not paid by the due date. If you can't lodge or pay in full and on time, the ATO asks you to contact it, or your registered tax professional, before the due date. You may be able to set up a payment plan.

The ATO can also apply a failure to lodge on time penalty to a late activity statement. The base penalty is one penalty unit for every 28 days, or part of 28 days, the statement is overdue, up to 5 penalty units, and it is multiplied for medium and large withholders. The ATO says it generally doesn't apply penalties for isolated late lodgments, warns you before applying one, and generally won't issue one for a late BAS that results in a refund or a nil result, with some exceptions. If you gave a registered agent everything they needed on time, safe harbour rules may mean you are not liable.

Checklist before you lodge

Sources

Related: Australia GST calculator ยท What an Australian tax invoice must show

Page last updated: 11 October 2026. Results are estimates for general information. See the terms.