A Business Activity Statement (BAS) is the ATO form that reports GST collected, GST credits claimed, PAYG withheld, and (where applicable) PAYG instalments and FBT for a quarter.
Quarterly BAS is due 28 days after the end of each quarter: Q1 (Jul–Sep) due 28 October, Q2 (Oct–Dec) due 28 February, Q3 (Jan–Mar) due 28 April, Q4 (Apr–Jun) due 28 July.
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Lodging through a registered tax agent or BAS agent gives you an extended due date (typically 4 weeks past the standard date).
Lodgement channels: ATO online services (myGovID), the ATO's business portal, a registered agent, or via SBR-enabled accounting software (PLS).
Late lodgement attracts Failure To Lodge (FTL) penalties — currently $313 per 28-day period for small entities (1 penalty unit), capped at 5 units.
A Business Activity Statement, or BAS, is a form submitted to the Australian Taxation Office (ATO) that reports your business's tax obligations. If you're registered for GST, PAYG withholding, PAYG instalments, or fringe benefits tax, you'll need to lodge a BAS — no exceptions.
Think of it as your regular check-in with the ATO. You're telling them how much GST you collected, how much you paid, and what other tax obligations you've met during the period.
Keeping your records organised throughout the quarter makes this step dramatically easier. If you're using accounting software like OneBookPlus, your sales and expense data is already categorised and ready to go.
Late lodgement attracts a penalty of $313 for each 28-day period (or part thereof) that the BAS is overdue, up to a maximum of $1,565. Set calendar reminders or use software that alerts you.
The ATO requires you to retain all business records for at least five years. Digital copies are perfectly acceptable — just make sure they're backed up.
The single best thing you can do is stay on top of your bookkeeping throughout the quarter. When BAS time rolls around, you should be reviewing and confirming numbers, not scrambling to enter three months of receipts.
Here's what makes the process painless:
Record expenses as they happen — snap a photo of receipts and log them immediately
Reconcile weekly — don't let transactions pile up
Use software that tracks GST automatically — every invoice and expense should have GST calculated and categorised
Separate GST-free and GST-inclusive transactions — your software should handle this, but double-check
OneBookPlus automatically calculates GST on every invoice and expense you create. At BAS time, you can pull up your GST summary report that shows exactly what you collected (1A) and what you paid (1B) for the period.
Key features that help with BAS:
Automatic GST calculations on all invoices and expenses
If you're still tracking GST in spreadsheets or shoeboxes, it's time to upgrade. OneBookPlus offers a free plan that includes invoicing, expense tracking, and GST reporting — everything you need to lodge your BAS with confidence. Start your free trial and let OneBookPlus handle your BAS summaries automatically.
