What does a BAS agent do? Core services
Think of a BAS agent as the specialist who turns your day-to-day records into compliant activity statements. Typical work includes:
- BAS/IAS preparation and lodgement: GST, PAYG withholding, PAYG instalments and eligible fuel tax credits, plus WET/LCT where relevant.
- Bookkeeping review: fix GST coding, reconcile bank/loan accounts, review supplier/customer GST status and correct common errors.
- Payroll and STP alignment: check PAYG withholding, leave and super calculations flow correctly into BAS and year-end STP finalisation.
- ATO communication: respond to ATO letters, request lodgement deferrals or payment plans and explain notices in plain English.
- Systems and setup: configure Xero, MYOB or QuickBooks tax codes, lodgement access (SBR), user roles and documentation.
If you need this done for your business, you can move straight to a short scoping call or a file review.
Australian context to keep in view
- BAS reports GST, PAYG withholding and instalments, and some industry taxes. Frequency is usually quarterly or monthly based on turnover and registrations.
- Lodgement timing matters. Quarterly BAS are generally due 28 days after quarter end. Monthly BAS are usually due on the 21st of the following month. Agent concessions may extend these dates.
- Only a registered BAS or tax agent can provide BAS services for a fee. Verify registration on the TPB public register.
- Choosing between a bookkeeper, BAS agent and accountant depends on scope. Use our comparison pages to match your need to the right provider.
What BAS agents can and cannot do
What they can do
Determine and advise on GST, PAYG-W and PAYG-I amounts; prepare and lodge BAS/IAS; help claim eligible fuel tax credits; fix GST coding; liaise with the ATO on BAS matters; set up compliant workflows.
What they cannot do
Prepare income tax returns or provide income tax advice unless also registered as a tax agent. For income tax, company tax or complex structuring, see an Australian tax accountant.
When to involve a bookkeeper
Routine data entry and reconciliations can be handled by a bookkeeper. Many providers bundle bookkeeping + BAS so the numbers flow cleanly into lodgements.
When to involve an accountant
For tax planning, business structuring, company returns, trusts or advisory, a small business accountant or tax agent is the right fit.
Deadlines and lodgement cycles
Understanding your cycle avoids penalties and cashflow surprises:
- Quarterly BAS: Generally due 28 April (Q3), 28 July (Q4), 28 October (Q1), 28 February (Q2, extended). Check for agent concessions.
- Monthly BAS: Usually due on the 21st of the following month.
- IAS: Often monthly for PAYG instalments or withholding where GST is not reported.
- Agent program: Registered agents may access ATO lodgement program concessions and can help request payment plans if needed.
If you are behind, a registered BAS agent can prioritise clean-up, lodge outstanding statements and manage ATO contact.
Step-by-step: from records to a lodged BAS
- Initial review: confirm registrations, reporting cycle and any ATO letters.
- Reconcile: bank, clearing, GST control and payroll accounts are reconciled to source documents.
- Fix coding: correct GST codes, supplier/customer GST treatment and non-deductible items.
- Calculate: GST on sales/purchases, PAYG-W, PAYG-I and fuel tax credits if applicable.
- Prepare and sign-off: generate BAS/IAS reports for approval with a clear payment or refund summary.
- Lodge and follow-up: lodge via SBR, confirm ATO receipt, and set any payment plan if required.
This process catches errors before they reach the ATO and builds clean data for future reporting and tax work.
What to compare before you commit
Scope
Confirm BAS/IAS, bookkeeping touch-ups, payroll/STP, ATO liaison and reporting needs. Ensure catch-up or migration work is included if relevant.
Software fit
Look for deep experience in your current platform (Xero, MYOB, QuickBooks) and a clear workflow for coding, reconciliation and lodgement.
Turnaround and communication
Agree on monthly/quarterly rhythms, file access, approval steps and how urgent issues are escalated near deadlines.
Commercial fit
Compare fixed-fee vs packages vs hourly, and whether you want compliance-only or ongoing advisory/management reporting.
Common scenarios a BAS agent handles
- New GST registration and first BAS setup, including software tax codes and ATO access.
- Quarterly or monthly BAS lodgements with clear payment schedules.
- Overdue BAS clean-ups and ATO payment plan requests.
- Payroll and STP reviews where PAYG-W isn’t matching activity statements.
- Fuel tax credits reviews for eligible vehicles and plant.
- File migrations or rebuilds so future BAS is faster and accurate.
Best next steps
Write down the exact outcome you want first: a lodged BAS, clean books, an ATO plan, or a faster month-end. Then shortlist providers against that outcome, not just a title.
Use these pages to go deeper before you reach out:
Frequently asked questions
What does a BAS agent do?
A BAS agent is TPB-registered to advise on and lodge BAS/IAS. They reconcile your file, calculate GST and PAYG amounts, correct coding, prepare the statements, lodge with the ATO and help with ATO correspondence and payment plans.
When should I use a BAS agent instead of a bookkeeper?
Use a BAS agent when you need BAS services provided for a fee—determining GST/PAYG, preparing and lodging BAS/IAS, and dealing with the ATO on BAS matters. A bookkeeper can manage daily processing but cannot provide BAS services for a fee unless registered.
How often do I need to lodge BAS and what are the deadlines?
Most businesses lodge quarterly (generally due 28 days after each quarter, with an extended February due date for Q2) or monthly (due on the 21st of the following month). Registered agents may access ATO concessions. Your exact dates depend on your ABN and lodgement cycle.
How do I check if someone is registered?
Search the TPB public register. Check their registration number and status. Registered BAS agents must hold PI insurance and meet education/experience and CPE requirements.
What is the safest next step?
Outline your BAS period, software, any overdue lodgements and ATO letters, then request a short file review with a registered BAS agent. Use the form below to get started.