How monthly BAS works, step‑by‑step
A dependable monthly BAS process reduces last‑minute stress and avoids ATO follow‑ups. Here’s the typical workflow a good BAS agent follows each month:
- Data capture: ensure all bank and card feeds are up to date and key source docs are available (large bills, imports, asset purchases).
- Coding and GST checks: apply correct GST codes for taxable, GST‑free, input‑taxed and mixed supplies; confirm cash vs accrual basis.
- Payroll review: confirm STP is filed, W1/W2 agree to payroll reports, and super is on track.
- Reconciliation: bank/credit card recs to statement, GST control to BAS summary, wages/payables/receivables to the balance sheet.
- BAS preparation: compile the monthly BAS, confirm adjustments (private use, bad debts, DGST on imports, fuel tax credits if relevant).
- Agent review and sign‑off: second‑pair review, client queries resolved, and approval captured.
- Lodgement and payment: e‑lodgement via SBR/Online Services for Agents; provide payment options and reference (PRN) for the Integrated Client Account.
Australian rules to keep in view
- Due date: monthly BAS is generally due on the 21st of the following month (next business day if it falls on a weekend/public holiday).
- Who reports monthly: businesses with GST turnover of $20m+ must report GST monthly; others may opt in for cash flow or credit timing.
- PAYG withholding: medium and large withholders report monthly; ensure W1/W2 align with payroll and STP.
- GST method: cash vs accrual must be applied consistently across income and expenses.
- Imports: check Deferred GST (DGST) statements and freight/customs docs to claim credits correctly.
- Software: Xero, MYOB, QuickBooks Online and similar tools support monthly BAS, but setup and tax code discipline are critical.
If you’re unsure whether monthly or quarterly BAS applies, use BAS Setup or ask a BAS agent for a quick check.
What to compare before you commit
Scope
Confirm monthly scope covers reconciliations, GST/W1‑W2 checks, adjustments, lodgement and ATO follow‑up, not just report pushing.
Registration and experience
Use a registered BAS agent or tax agent. Ask for examples of monthly workflows for businesses like yours.
Turnaround and communication
Agree on cut‑off dates, typical response times and escalation during peak periods (e.g., 18–21st).
Software fit
Ensure deep knowledge of your stack (e.g., Xero + add‑ons, MYOB, QBO) and how reports reconcile back to source.
Commercial fit
Check fees, fixed vs variable pricing, meeting cadence and whether you need compliance only or advisory as well.
Data security
Clarify user access, document handling, 2FA and records retention for ATO review.
What a monthly BAS agent typically delivers
- Clean bank recs and consistent GST coding across sales, purchases and mixed supplies.
- Payroll to BAS alignment (W1/W2 to STP and payroll reports).
- Supporting workpapers showing how BAS figures reconcile to the ledger.
- Electronic lodgement and clear payment instructions before the 21st.
- ATO correspondence handling and follow‑ups on your behalf (as authorised).
- Proactive flags: private use adjustments, bad debts, capital acquisitions, DGST, FTC and industry‑specific issues.
Need one‑off help first? See BAS Review for a pre‑lodgement check or BAS Corrections if figures were lodged incorrectly.
Pricing guide for monthly BAS
Prices vary by volume, payroll complexity, and how tidy the file is:
- Micro (very low transactions, no payroll): typically $120–$250/month.
- Small (steady volume, simple payroll): typically $250–$600/month.
- Medium to higher complexity (projects, imports, multiple systems): $600–$2,000+ per month.
Initial setup or catch‑up work (if you are behind) is quoted separately. See BAS Catch Up Services if you have overdue months.
Common monthly BAS issues that cause rework
- Mixed supplies not split correctly (GST‑free components within taxable invoices).
- Incorrect GST codes on overseas purchases, imports or reverse‑charged services.
- Cash vs accrual mismatch between sales invoices and BAS settings.
- W1/W2 not reconciled to payroll/STP or super not accrued correctly.
- Asset purchases treated as expenses; missing tax invoices for large credits.
- Unapplied payments or duplicated bank feed items inflating GST.
If you spot these, pause and request a BAS Review before lodging.
Best next steps
Decide whether you need setup, a clean‑up, or ongoing monthly BAS. Note your software, transaction volume, payroll headcount and any ATO deadlines.
Shortlist providers who explain their monthly process clearly and can show how BAS figures reconcile to your ledger. Use the links below if you need a narrower topic first:
- BAS Lodgement for straight‑through lodgement.
- BAS Review for a second set of eyes before lodging.
- BAS Corrections if prior BAS returns need amending.
- Bookkeeping Services if the file needs ongoing tidy‑up.
- Payroll Services to align W1/W2 with STP.
- Tax if you also need broader tax planning.
Frequently asked questions
What is monthly BAS and who needs it?
Monthly BAS is a Business Activity Statement lodged every month to report GST and, where relevant, PAYG withholding and other taxes to the ATO. It’s mandatory for businesses with GST turnover of $20 million or more, and optional for others who prefer monthly reporting or have monthly withholding obligations.
When is monthly BAS due?
It’s generally due by the 21st of the following month. If the 21st is a weekend or public holiday, the due date is the next business day. Monthly lodgers typically don’t receive the longer concessions some quarterly lodgers get.
What does a monthly BAS service include?
Bank/credit feed reconciliation, GST coding checks, payroll/W1‑W2 verification, balance sheet reconciliations, BAS preparation and review, electronic lodgement, and clear payment instructions. Good providers also handle ATO correspondence and flag adjustments like DGST, FTC or private use.
Do BAS agents get extra time for monthly BAS?
Not usually. The 21st deadline still applies to monthly reporters. An agent may seek a deferral in specific cases, but it isn’t automatic.
How much does monthly BAS help cost?
Indicative fees range from $120–$250/month for micro entities, $250–$600 for small businesses, and $600–$2,000+ for higher complexity. Setup or catch‑up work is separate.
What records do I need to provide each month?
Up‑to‑date bank recs, tax invoices for large credits, payroll/STP reports, import/DGST statements, and details of any adjustments or unusual transactions.