BAS Lodgement Guide: When, How, and What Australian Businesses Need to Report

If your business is registered for GST, lodging a Business Activity Statement (BAS) is not optional. With STP Phase 2 now mandatory, accurate payroll reporting supports your BAS process. Here's a practical guide to getting it right and avoiding ATO penalties.

What Is a BAS?

A Business Activity Statement is a form submitted to the Australian Taxation Office (ATO) that reports your GST, PAYG withholding, PAYG instalments, and other tax obligations.

When Is Your BAS Due?

| Lodgement Frequency | Due Date | | ------------------------------- | ------------------------------------------- | | Monthly | 21st day of the following month | | Quarterly ( lodged by you) | 28 days after the end of the quarter | | Quarterly (lodged by tax agent) | Usually 28 days after the standard due date |

Key quarterly dates for 2026:

• Q3 (Jan–Mar): 28 April 2026
• Q4 (Apr–Jun): 28 July 2026

How to Lodge

1. Online via myGov — Linked to the ATO, this is the simplest method for most small businesses
2. Through your accountant or tax agent — Recommended if your affairs are complex
3. By phone — Available for businesses that report the same amount each period
4. By mail — Paper BAS forms are still available but take longer to process

What to Report

Your BAS typically includes:

• GST — GST on sales (1A) and GST on purchases (1B)
• PAYG withholding — Tax withheld from employee wages
• PAYG instalments — Pre-paid income tax for the year
• FBT instalments — If applicable

Common Mistakes

• Missing the deadline — The ATO charges a failure-to-lodge penalty of $313 per 28-day period (up to $1,565 for individuals)
• Incorrect GST classification — Ensure you understand what is and isn't subject to GST
• Not reconciling before lodging — Cross-check your BAS figures against your accounting software
• Forgetting to claim credits — You're entitled to GST credits on business purchases

How Reguladar Helps

Reguladar tracks your BAS due dates, sends reminders before each deadline, and shows you exactly what needs to be lodged — alongside all your other small business compliance obligations. Never miss a BAS deadline again.

Try Reguladar free to see your upcoming tax obligations.