Skip to content

GST & BAS

Understanding BAS and GST Reporting

What a Business Activity Statement reports, the main BAS labels (G1, 1A, 1B, W1, W2), due dates, Simpler BAS and how to avoid common BAS errors.

Published 2 min readGST & BASSmall Business Tax

Key takeaways

  • Your BAS reports GST, PAYG withholding, PAYG instalments and other taxes.
  • Quarterly BAS is generally due on the 28th of the month after the quarter (Q2: 28 February).
  • Businesses under $10 million turnover generally use Simpler BAS for GST.
  • Reconcile your accounts before every BAS — not after.

A Business Activity Statement (BAS) is how businesses report and pay several tax obligations to the ATO. Understanding what each section means makes BAS time far less stressful.

What a BAS reports

Most businesses with GST turnover under $10 million report GST using Simpler BAS, which only requires G1, 1A and 1B for the GST section.

Common BAS labels
LabelWhat it reports
G1Total sales, including GST
1AGST collected on sales
1BGST credits on purchases
W1Total wages paid
W2Tax withheld from wages and other payments
T7 / 5APAYG income tax instalment

Due dates

Monthly BAS is generally due on the 21st of the following month. Businesses with GST turnover of $20 million or more must report monthly. Different due dates may apply when lodging through a registered agent.

Quarterly BAS due dates (lodging yourself)
QuarterPeriodGenerally due
Q1July – September28 October
Q2October – December28 February
Q3January – March28 April
Q4April – June28 July

Preparing an accurate BAS

  • Reconcile every bank and credit card account for the period
  • Check GST coding — especially GST-free and input-taxed items
  • Make sure you hold tax invoices for credits over $82.50
  • Separate capital purchases from other purchases
  • Exclude private expenses and wages paid to yourself as a sole trader
  • Match PAYG withholding to your payroll reports

If you can't pay

Lodge on time anyway. Failure-to-lodge penalties are separate from the amount owing, and the ATO offers payment plans for eligible debts.

General information only. This article doesn't take into account your personal circumstances and isn't a substitute for professional advice. Tax rules and thresholds change — check current details with the ATO or contact us for advice specific to you.

Published by

ANS Taxation & Accounting

Melbourne accounting and tax practice

Registered Tax Agent26382734Tax Practitioners Board · Verify ↗

Ready for clearer numbers?

Book a consultation and let's talk about your tax, accounting or bookkeeping needs. No obligation — just a clear conversation about how we can help.

Call Us TodayBook a Consultation