Your September checklist for the 28 October BAS

Why late September is the sweet spot

Most BAS stress comes from trying to fix three months of records in the week before the deadline. Working in late September — while the quarter is still fresh — means you remember what that odd transaction was, receipts are still findable, and there's time to chase missing invoices before anyone's under pressure.

It's also the moment to check cash flow. The BAS payment and the super payment land together, so knowing the rough size of both a month ahead beats being surprised twice on the same day.

The checklist

Set aside 45–60 minutes a week for the rest of September and work through these:

• Reconcile July and August bank feeds now, so only September is left once the quarter closes.
• Capture receipts for anything with GST — snap them from your phone into QBO, Xero or MYOB before they fade or go missing.
• Send any outstanding invoices and follow up overdue ones — income received before 30 September counts in this quarter.
• Check payroll is posted and STP reported for every pay run in the quarter.
• Confirm super for the quarter is calculated, and note that payment is due 28 October alongside the BAS.
• Set aside the GST and PAYG you've collected in a separate account so the payment never surprises you.

Two dates, one day

It's easy to focus on the BAS and forget that super guarantee contributions for the September quarter are due on the same date — 28 October. Super must be received by the fund by the due date, so leaving it to the last day or two is risky; paying via your clearing house a week or more early is the safer habit.

And with Payday Super commencing from 1 July 2026 — where super is paid with each pay run rather than quarterly — these quarterly super deadlines are transitioning to a more frequent rhythm. If you're not sure how the change affects your pay cycle, it's worth a conversation now rather than next year.

Falling behind? Do it in the right order

If July and August are still untidy, don't try to perfect everything at once. Reconcile the bank first (it proves most of your figures), then GST receipts, then payroll. Even a rough picture by early October gives your bookkeeper or BAS agent something to work with — and lodging through a registered BAS agent can give you access to extended lodgement dates.

If the quarter is already a write-off and the shoebox is winning, that's exactly what catch-up work is for. A few focused hours from a bookkeeper in early October beats a panicked weekend on the 26th.