BAS Preparation Checklist Australia

G1 is Total Sales on the BAS — it includes all your business sales for the period: taxable sales (where you charge 10% GST), GST-free sales (e.g. basic food, medical services, exports), input-taxed sales (e.g. residential rent), and export sales. G1 is your total revenue before deducting any expenses.

Quarterly BAS due dates: Q1 (Jul–Sep) due 28 October; Q2 (Oct–Dec) due 28 February; Q3 (Jan–Mar) due 28 April; Q4 (Apr–Jun) due 28 July. Monthly lodgers must lodge by the 21st of the following month. Lodging through a registered tax agent typically provides extended due dates.

G10 covers capital acquisitions — purchases of business assets like machinery, vehicles, computers and equipment where you can claim the GST input tax credit. G11 covers all other acquisitions with GST — regular operating expenses like rent, utilities, supplies and professional services. Both attract GST credits when you're registered.

You need: all tax invoices for sales and purchases during the period, bank statements, payroll records (wages paid and PAYG withheld), details of any fuel purchases for fuel tax credits, and records of fringe benefits provided to employees. Maintaining accurate bookkeeping throughout the quarter makes BAS preparation far more straightforward.

You can lodge your own BAS directly through the ATO's Business Portal or your accounting software (Xero, MYOB, QuickBooks). However, a registered BAS agent or tax agent can lodge on your behalf, often with an extended due date and can help ensure accuracy. For complex situations involving FBT, fuel tax credits or mixed supplies, professional advice is recommended.