Running a small or medium business in Australia means staying on top of your tax and compliance obligations and the quarterly (or monthly) Business Activity Statement (BAS) is one of the most important tasks. But with changing regulations, GST, PAYG, and bookkeeping complexity, many SMEs make avoidable mistakes that lead to penalties. This guide breaks down everything you need to know for smooth, accurate BAS lodgement in 2025
What is BAS & Who Needs to Lodge It
BAS is the ATO’s activity statement used to report GST collected/paid, PAYG withholding/instalments, and other tax obligations (if any)
All businesses registered for GST are required to lodge BAS even if in a given period you have nothing to report ("nil" BAS must still be submitted)
The lodgement frequency depends on turnover and business size
Monthly usually for large businesses (e.g. GST turnover above certain threshold)
Quarterly common for most SMEs under that threshold
Key Deadlines & Reporting Periods for 2025
For quarterly BAS: the due dates are typically the 28th of the month following the end of each quarter. Example: Quarter ending 30 September → BAS due 28 October
For monthly BAS (if required): BAS is usually due by the 21st day of the following month
Even if there is "nil activity" (no sales, GST, or PAYG), you still must lodge the BAS by the due date
Common BAS & GST Mistakes Australian SMEs Make
Many SMEs accidentally fall foul of compliance. Common issues
Late lodgement or payment exposing business to penalties & interest
Incorrect calculation of GST (charged vs purchases), leading to under- or over‑payment
Poor record‑keeping: missing tax invoices, receipts, or proper digital records which can cause problems during audits
Misreporting PAYG withholding or instalments especially if you have employees or forgetting to lodge when required
How to Lodge BAS Correctly Step by Step Guide
Keep accurate bookkeeping records all sales, purchases, expenses, PAYG, GST, et
Reconcile your accounts regularly (bank, sales, purchases) to ensure data accuracy
Use cloud‑based accounting software (e.g. Xero, MYOB, QuickBooks Online) that integrates with ATO and helps with GST tracking & BAS calculation
Lodge electronically via ATO’s online services or through a registered BAS/tax agent it’s faster, more secure, and you may get extra lodgement time
Even if you owe nothing (nil), lodge a nil BAS failing to lodge can trigger penalties
Why Regular & Accurate BAS Matters for Your Business
Helps maintain compliance with ATO avoiding fines, interest, and negative compliance history
Maintains clean and up-to-date financial records critical for cash flow analysis, business planning, budgeting, and growth
Supports transparent GST & tax handling ensures you claim correct input tax credits and pay only what's required
Builds confidence for investors, lenders, and stakeholders especially if you need funding, apply for grants, or want to scale the business
How Online Bookkeeping & Pars Business Solutions Can Help
As a full‑service bookkeeping & advisory firm, Pars Business Solutions
Manages your BAS, GST, and PAYG obligations end-to-end reducing your admin burden
Uses cloud‑accounting systems to guarantee accuracy, real-time access, and transparent reporting
Keeps your records audit-ready and compliant with ATO standards
Provides timely lodgement and payment reminders so you never miss a deadline helping you avoid penalties and interest
Gives you financial clarity and insights enabling smarter business decisions and growth
Don’t let BAS stress eat up your time
Let Pars Business Solutions make your BAS lodgement simple, accurate, and stress‑free
Book your consultation today and stay ahead of compliance
?Q: Who must lodge a BAS
A: Any business registered for GST and any business with PAYG withholding or instalments obligations
?Q: How often do I need to lodge BAS
A: Depending on your business turnover/size: most SMEs lodge quarterly; large businesses may lodge monthly; some small ones may be eligible for annual instalment arrangements (subject to ATO guidelines)
?Q: What happens if I lodge late or incorrectly
A: You may face penalties, interest charges, and possibly be moved from quarterly to monthly reporting if you have history of non‑compliance
?Q: Can I lodge a “nil BAS
A: Yes even if no activity. You must lodge by due date to stay compliant
?Q: What records do I need to keep
A: All invoices, sales receipts, purchase receipts, expense records, payroll and PAYG records for at least 5 years per ATO record‑keeping rules
