A rough guide, not a lodgement, adjustments, PAYG and the unusual stuff aren't in it.
The BAS in one paragraph
Once your ABN carries a GST registration, you lodge a business activity statement each cycle (quarterly for most). Its GST heart is a simple netting: one-eleventh of your taxable sales is GST you collected for the ATO; one-eleventh of your GST-carrying costs is credit coming back to you. Collected minus credits is the payment, or, in plenty of quarters, the refund.
Getting the two inputs right
- Sales: use the GST-inclusive totals customers actually paid you, and only for taxable sales. GST-free income doesn't generate GST to remit.
- Costs: only the ones with GST in the price. Wages never have GST. Neither do most bank charges, many insurances, or subscriptions billed from overseas without GST. Padding this box overstates the refund and gets unwound later.
Refund quarters are normal
New businesses spend before they earn, a quarter where you fitted out a workshop, bought a vehicle or stocked up will often show credits above collections, and the difference is paid back to you. It's one of the practical reasons some businesses register for GST before they're forced to. If your ABN isn't GST-registered yet, none of this applies, no GST on sales, no credits on costs.
Quick answers
Is this what my actual BAS will say?
The GST arithmetic is exact for the numbers you enter; the real form adds anything unusual, adjustments, PAYG amounts, private-use apportionment. Treat it as the GST core, not the finished statement.
What if I had no sales this quarter?
You still lodge (a nil or refund BAS), and if you spent on GST-carrying costs you'll usually get credits back. Skipping the lodgement is what causes penalties, not the zero.
Do wages go in the costs box?
No, wages carry no GST, so they generate no credit. If you withhold tax from employees' pay, that's reported on separate BAS labels, outside this estimate.
I don't have GST registered on my ABN: do I lodge a BAS?
No BAS without a GST (or PAYG) registration, but also no credits on anything you buy. Whether to add GST to your ABN is a threshold and cash-flow question worth checking early.
Related: Do I need to register for GST? · GST calculator · All business calculators
ABN first, GST second. We do both in one pass.
Registered Tax Agent 26076969 · usually same-day · free help on 1800 546 526.