BAS & IAS
Lodgement Services
Registered BAS agent support for quarterly BAS, monthly IAS, GST reconciliation, PAYG withholding and catch-up BAS work for Australian businesses using Xero, MYOB or QuickBooks.
Australian Standards
Quarterly BAS & monthly IAS
We manage the right lodgement rhythm for your business, from quarterly BAS to monthly IAS and PAYG obligations.
GST, PAYG & payroll cross-checks
Transactions, GST coding, PAYG withholding and STP data are reviewed before lodgement so issues are caught early.
Catch-up BAS and corrections
If you're behind or a previous BAS was wrong, we can help clean up prior periods and prepare revisions where needed.
Clear activity statements, fewer surprises at lodgement time.
Whether you need quarterly BAS, monthly IAS, GST reviews or help fixing past lodgements, Numberz gives you a more accurate and less stressful BAS process.
Registered BAS agent review before lodgement
Support for Xero, MYOB and QuickBooks files
Quarterly BAS, monthly IAS and catch-up lodgements
Clear guidance when previous BAS periods need fixing
BAS preparation & lodgement
- Quarterly BAS and monthly IAS lodgements
- GST, PAYG withholding and PAYG instalment reporting
- ATO-ready workpapers and review notes
- Lodgement tracking so deadlines are never missed
Reconciliation & review
- GST coding and transaction review across Xero, MYOB or QuickBooks
- Payroll and STP cross-checking before submission
- Anomaly detection for missing, duplicate or miscoded entries
- Cash-flow visibility for upcoming GST and PAYG liabilities
Catch-up, clean-up & corrections
- Late BAS catch-up work for overdue periods
- Correction of prior-period errors under ATO rules
- Revision support for material mistakes
- Practical guidance on payment planning and next steps
Know what you need to lodge and when it is due.
BAS and IAS get confused all the time. This section makes the differences clearer and shows the due dates most businesses care about.
Business Activity Statement (BAS)
A BAS reports GST, PAYG withholding, PAYG instalments and other tax obligations to the ATO. Most Australian small businesses lodge quarterly, while larger businesses may lodge monthly.
Instalment Activity Statement (IAS)
An IAS usually applies when you need to report PAYG withholding and/or PAYG instalments more frequently than GST. It's common for employers who have payroll obligations but don't lodge GST monthly.
Quarterly BAS due dates
Common due dates when using a registered tax agent.
| Quarter | Period | Due date |
|---|---|---|
| Q1 | July – September | 25 November |
| Q2 | October – December | 28 February |
| Q3 | January – March | 28 May |
| Q4 | April – June | 25 August |
Monthly BAS or IAS
Monthly BAS and many IAS obligations are generally due on the 21st of the following month.
Behind on lodgements?
We can review overdue periods, prioritise urgent BAS items and help get your account back into order.
Better BAS and IAS support than a basic once-a-quarter lodgement.
Good activity statement work is more than filing a form. It should improve accuracy, reduce deadline risk and help you see what is coming next.
GST reconciliation that catches coding issues early
We review GST collected and GST paid against your ledger so coding errors, missing tax codes and unusual claims are picked up before lodgement.
PAYG withholding and instalments reviewed together
PAYG withholding from wages and PAYG instalments are checked together with payroll and prior-period data so the ATO figures line up.
STP cross-checking before you lodge
Single Touch Payroll figures are compared against your activity statement to reduce avoidable discrepancies and clean-up later.
Deadline management with less last-minute stress
We manage preparation windows, review checkpoints and due dates so your BAS or IAS is ready before the deadline, not on it.
Error detection for unusual claims and omissions
Duplicate entries, inconsistent coding and unusual GST claims are flagged before lodgement so they can be reviewed with context.
Cash-flow visibility around upcoming ATO payments
Understand what GST and PAYG will likely be due before the lodgement date, helping you plan cash flow and avoid nasty surprises.
BAS and IAS done right, every cycle.
The process mirrors your strongest accounting pages: clearer handoff points, better review discipline and a simpler client experience from first review to ATO lodgement.
Review your file and lodgement history
We look at your accounting file, payroll setup, GST settings and recent BAS or IAS lodgements so we know exactly what needs attention.
Reconcile GST, PAYG and key balances
Transactions, GST coding, PAYG withholding and STP data are reconciled to identify mismatches, omissions and items that need clarification.
Registered BAS agent review
A registered BAS agent reviews the numbers, adjustments and supporting workpapers before anything is prepared for lodgement.
Lodge and plan the next due date
Once approved, we lodge with the ATO and give you a clear summary of what was filed, what is payable and what the next deadline looks like.
Common BAS & IAS Questions
The answers below cover the questions Australian businesses ask most often before outsourcing BAS or IAS work.
Get BAS and IAS handled properly before the next deadline lands.
If your business needs a cleaner BAS process, better GST review discipline or help catching up overdue periods, we can map out the next steps in a free review.