GST and BAS Guide: When to Register and How to Lodge on Time

Goods and Services Tax (GST) is a broad-based 10% tax applied to most goods, services, and other items sold or consumed in Australia. Businesses that are registered collect one-eleventh of the GST-inclusive price from their customers and remit it to the ATO, less any GST credits for GST included in business purchases. GST is reported through the Business Activity Statement (BAS), usually quarterly, and getting registration, accounting method, and lodgment timing right avoids avoidable penalties and cash-flow shocks.

When GST registration is mandatory

• When your business has a current or projected GST turnover of $75,000 or more ($150,000 for non-profit bodies).
• When you provide taxi, limousine, or ride-sourcing services (such as Uber) regardless of turnover.
• When you want to claim fuel tax credits for business use of fuels.

Registration is required within 21 days of reaching the threshold, and back-registration applies from the date you were first required to register — which can create a GST liability you had not budgeted for. Voluntary registration is also available for businesses below the threshold, and is worthwhile where your customers are GST-registered themselves and your inputs carry GST you could otherwise claim back.

Cash or accruals accounting

Under the accruals method, GST is reported on the date of an invoice, regardless of when payment occurs. This is mandatory for some larger businesses and can be preferable where there is a timing mismatch between invoicing and payment, but it generally creates a larger working-capital burden because GST is remitted before the cash is received.

Quarterly BAS lodgment due dates

Standard quarterly BAS lodgment due dates are 28 October (Q1), 28 February (Q2), 28 April (Q3), and 28 July (Q4). When you lodge through a registered tax agent like Freedom Taxation, you receive automatic extensions — typically around four weeks — for every quarterly lodgment, which eases the year-end reconciliation burden and gives you time to resolve any bookkeeping discrepancies before lodgment.

Common GST mistakes to avoid

• Claiming GST credits on purchases used for private purposes (only the business portion is creditable)
• Treating GST-free sales (exports, most food, education, health) as taxable sales
• Failing to back-register when turnover crosses $75,000 mid-year
• Claiming credits without a valid tax invoice for purchases over $82.50 (GST-inclusive)
• Not adjusting the GST rate on imported services and digital products where reverse-charge applies

GST is fundamentally a transaction tax that rewards good bookkeeping. A clean ledger where every transaction is coded to the right GST treatment makes the BAS a five-minute exercise; a messy one turns it into a costly reconciliation. Freedom Taxation reviews the BAS each quarter, reconciles the GST accounts before lodgment, and flags any transactions that need an adjustment before they become a problem in an ATO review.