Key takeaways
- Mixing personal and business spending is the most common — and costly — mistake.
- Reconcile at least monthly, not just at BAS time.
- GST coding errors flow straight into your BAS.
- Under Payday Super, super now needs to be paid with every pay run.
Most bookkeeping problems aren't complicated — they're small habits that compound until BAS or tax time. Here are the mistakes we see most often.
Ten mistakes to avoid
- Using one bank account for business and personal spending
- Only reconciling accounts when the BAS is due
- Losing receipts and tax invoices for GST credits
- Coding GST-free or input-taxed items as taxable (or the reverse)
- Treating capital purchases as everyday expenses
- Recording owner drawings as business expenses
- Not setting aside GST and income tax as money comes in
- Paying super late — now a per-payday obligation under Payday Super
- Treating workers as contractors when they're legally employees
- Ignoring overdue customer invoices
Why it matters
Errors in your books flow directly into your BAS and tax return. Fixing them later takes longer, can attract penalties and interest, and leaves you making decisions on unreliable numbers.
A simple routine that works
- Weekly: capture receipts and code new transactions
- Monthly: reconcile all accounts and review profit and loss
- Each pay run: process payroll, STP and super together
- Quarterly: review GST coding before preparing the BAS
Official sources
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