Quarterly BAS Preparation Checklist
Quarterly BAS preparation checklist for sole traders and small businesses. Walks through bank feed reconciliation, GST coding review, PAYG withholding verification, PAYG instalment amount or rate check, and lodgement by the deadline. Quarterly BAS is due 28 days after the end of the quarter (except Q2, which is due 28 February). Electronic lodgement through a registered tax agent gets an additional two weeks for most quarters.
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Start 7 days before the due date
Begin BAS preparation at least one week before the lodgement deadline. This gives you time to chase missing invoices, resolve unmatched bank transactions, and correct coding errors without rushing on the due date.
Reconcile, then review GST codes
Reconcile all bank feeds in your accounting software first. Then review the GST coding on every transaction for the quarter. Common errors: personal expenses coded as business, GST claimed on GST-free supplies (basic food, medical, education), GST claimed without a valid tax invoice for purchases over AUD 82.50.
Verify PAYG withholding against payroll
If you have employees, cross-check the PAYG withholding total on the BAS (labels W1 and W2) against your payroll reports for the quarter. Reconcile to your STP submissions. The BAS amount must match what you actually withheld from employees.
Lodge and pay by the deadline
Lodge electronically via myGov, ATO Online Services for Business, or through your registered tax agent (who gets extended deadlines for most quarters). Pay by the same due date. If you cannot pay in full, lodge on time anyway to avoid the late lodgement penalty, then contact the ATO about a payment plan.
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QUARTERLY BAS PREPARATION CHECKLIST - FY2025-26 ================================================ Business name: ______________________________ ABN: ______________________________ Quarter: [ ] Q1 Jul-Sep [ ] Q2 Oct-Dec [ ] Q3 Jan-Mar [ ] Q4 Apr-Jun Due date: ______________________________ Prepared by: ______________________________ DEADLINE REFERENCE (self-lodgers): Q1 (Jul-Sep 2025): 28 October 2025 Q2 (Oct-Dec 2025): 28 February 2026 Q3 (Jan-Mar 2026): 28 April 2026 Q4 (Apr-Jun 2026): 28 July 2026 SECTION 1: PRE-LODGEMENT RECONCILIATION [ ] All bank feeds imported and matched for the quarter Bank account(s): ______________________________ Unmatched transactions: _________ (resolve before proceeding) [ ] Petty cash reconciled and receipts filed [ ] Credit card statements reconciled [ ] All sales invoices for the quarter entered [ ] All purchase invoices for the quarter entered [ ] Intercompany or related-party transactions reviewed [ ] Suspense account cleared (no unallocated items) SECTION 2: GST REVIEW (labels 1A, 1B, G1-G20) [ ] GST on sales (label 1A) reconciled to sales report 1A total: AUD ___________ [ ] GST on purchases (label 1B) reconciled to purchases report 1B total: AUD ___________ [ ] GST-free sales correctly coded (no GST charged on basic food, medical services, education, exports) [ ] Input-taxed sales correctly coded (residential rent, financial supplies) - no GST credits claimable on related expenses [ ] Tax invoices held for all purchases where GST credit claimed and purchase exceeds AUD 82.50 [ ] No GST claimed on: [ ] Private expenses [ ] Wages and super contributions [ ] Bank fees on business accounts (check - some are GST-free) [ ] Government charges (most are GST-free) [ ] Insurance (check - some policies include GST, some do not) [ ] Cash vs accruals basis correctly applied per your elected method [ ] Adjustments for bad debts written off during the quarter (claim back GST on accruals basis if debt older than 12 months) [ ] Capital purchases over AUD 1,000 reviewed for correct GST and depreciation treatment SECTION 3: PAYG WITHHOLDING (labels W1-W5) - skip if no employees [ ] Total gross wages paid during quarter: AUD ___________ Label W1 total: AUD ___________ [ ] Total PAYG withheld during quarter: AUD ___________ Label W2 total: AUD ___________ [ ] W2 amount reconciled to payroll software / STP reports [ ] Contractor payments reviewed - withholding required if no ABN quoted (47% withholding, label W4) [ ] Director fees / related-party payments included if applicable SECTION 4: PAYG INSTALMENTS (label T7 or T8) [ ] Method confirmed: [ ] Instalment amount (T7) [ ] Instalment rate (T8) If instalment amount (T7): [ ] ATO-notified amount for the quarter: AUD ___________ [ ] Varied amount (if applicable): AUD ___________ [ ] Reason for variation documented If instalment rate (T8): [ ] Instalment income for the quarter: AUD ___________ [ ] ATO-notified rate: ___________% [ ] Instalment amount = income x rate: AUD ___________ [ ] Consider varying the instalment if current-year income is significantly different from the base year SECTION 5: FINAL CHECKS AND LODGEMENT [ ] BAS labels cross-checked against accounting software BAS report [ ] Net amount calculated: GST payable (1A): AUD ___________ GST refundable (1B): AUD ___________ PAYG withholding (W2): AUD ___________ PAYG instalment (T7/T8): AUD ___________ Net amount payable / refundable: AUD ___________ [ ] BAS lodged electronically Date lodged: ___________ Method: [ ] myGov [ ] Online Services for Business [ ] Tax agent [ ] Payment made (if net amount payable) Amount: AUD ___________ Payment method: [ ] BPAY [ ] Direct debit [ ] Credit card Date paid: ___________ [ ] Copy of lodged BAS saved to records [ ] Next quarter start date noted: ___________ Notes: - Lodge on time even if you cannot pay - avoids the late lodgement penalty. - One penalty unit = AUD 330 (from 1 July 2025) per 28-day late period, up to 5 units. - Tax agents typically get extended due dates (2-4 weeks beyond self-lodger dates). - If varying your PAYG instalment, you must have reasonable grounds or penalties may apply.
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