GST BAS lodgement preparation checklist
Incorrect BAS lodgement is one of the most common triggers for ATO review activity. This checklist helps practitioners and business owners prepare an accurate BAS by reconciling GST collected and claimed before lodgement.
This is a 12-step checklist for preparing a Business Activity Statement (BAS) for GST obligations under the GST Act 1999 (Cth). It covers GST reconciliation, input tax credits, reporting periods, and lodgement deadlines.
The checklist
Confirm reporting period
Identify whether the entity reports monthly, quarterly, or annually and confirm the period end date.
Reconcile sales to GST collected
Reconcile total sales for the period against GST collected at labels 1A and 1B on the BAS.
Review GST-free and input-taxed supplies
Ensure GST-free (Division 38) and input-taxed (Division 40) supplies are correctly excluded from GST calculations.
Verify input tax credits
Confirm all claimed input tax credits are supported by valid tax invoices and relate to creditable acquisitions under Division 11.
Check capital acquisitions
Separately identify and correctly report capital acquisitions at label 1B of the BAS.
Assess adjustment events
Identify any adjustment events under Division 19, such as price changes or cancelled supplies, and report at label 7A.
Review PAYG instalment amount
Calculate or verify the PAYG instalment amount (label T7 or T8) based on the instalment rate or varied amount.
Reconcile PAYG withholding
Reconcile PAYG withholding for the period against wages paid and report at label W1 and W2.
Check fuel tax credits
If applicable, calculate fuel tax credits and report at label 7C using current ATO rates.
Perform final reconciliation
Cross-check the BAS totals against the accounting system trial balance to identify discrepancies.
Lodge by the due date
Lodge the BAS electronically by the due date. Quarterly BAS is generally due 28 days after the quarter end; tax agent extensions may apply.
Retain records
Retain all source documents, tax invoices, and working papers for the ATO record-keeping period of five years.
When this checklist applies
Use before each BAS lodgement cycle or when preparing BAS for a new client to establish a reliable process.
Common pitfalls
- Claiming input tax credits without valid tax invoices
- Misclassifying input-taxed supplies as GST-free
- Overlooking adjustment events from prior periods
- Lodging late and triggering failure-to-lodge penalties
- Not reconciling BAS labels back to the general ledger
Run this checklist on a real matter
Quillio can reconcile GST data against lodgement labels, flag missing tax invoices, and identify common classification errors. See /practice-areas/tax-lawyers or start a free trial.
General GST BAS guidance. Complex supplies, grouping provisions, and margin scheme calculations require specialist tax advice.
Use this checklist on your matter.
Quillio can run this checklist on a specific NSW conveyancing matter — confirm each item, calculate adjustments, and generate the supporting documents. The free trial requires no credit card.
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