Fees, Cost Drivers and 2026 Rules
BAS and GST lodgement costs: what a BAS agent charges for and how to reduce it
What goes into preparing an Australian business activity statement, monthly vs quarterly vs annual GST reporting, Simpler BAS, due dates and how to lower the cost of each lodgement.
The cost of a BAS depends far less on the form than on the books behind it. A BAS for a small business using Simpler BAS, with reconciled bank feeds and correct GST codes, can be a short review. The same BAS from unreconciled accounts with mixed personal spending can take hours. You pay that cost once a quarter for most small businesses, or every month if you report monthly, so small improvements multiply. Reporting frequency, the number of obligations on the BAS (GST, PAYG withholding, PAYG instalments, fuel tax credits) and whether a registered agent lodges for you are the other drivers.
This guide is part of the small business accountant fees overview. Fees shown are illustrative.
What is on a BAS
| Obligation | Who has it | What the agent checks |
|---|---|---|
| GST on sales and purchases | GST-registered businesses | Every transaction has the right GST code; tax invoices exist for credits |
| PAYG withholding | Employers and businesses paying certain contractors | Withheld amounts match payroll and STP |
| PAYG instalments | Businesses and individuals with instalment notices | Correct instalment amount or rate; whether to vary |
| Fuel tax credits | Eligible business fuel users | Litres, eligible activities and current rates |
| Other items | Some businesses: wine tax, luxury car tax, FBT instalments | Specialist calculations |
How often you lodge
- Quarterly is the default for most small businesses with GST turnover under $20 million. Quarterly BAS due dates are generally 28 October, 28 February, 28 April and 28 July.
- Monthly is required for GST turnover of $20 million or more, and can be chosen by smaller businesses (some do so for cash-flow reasons when they receive regular GST refunds). Monthly BAS is generally due on the 21st of the following month.
- Annual GST reporting is available to businesses voluntarily registered for GST with turnover under the $75,000 threshold.
Registered BAS and tax agents lodging electronically may have later due dates for some quarters under the ATO's lodgement program concessions. Ask your agent for their dates in writing; do not assume a concession applies to you.
Simpler BAS and GST accounting methods
Small businesses with GST turnover under $10 million generally report GST on a Simpler BAS: total sales, GST on sales and GST on purchases. Fewer labels mean less work and fewer ways to get it wrong, though the underlying GST coding still has to be right.
You can usually account for GST on a cash basis if your aggregated turnover is under $10 million, meaning GST is reported when you are paid and when you pay suppliers. Accrual (non-cash) accounting reports GST when you issue or receive invoices. Cash accounting is simpler for many small businesses and can help cash flow, but it must match how your software is set up.
Worked example: one year of BAS costs
An illustrative café, registered for GST, with three employees, quarterly reporting.
| Scenario | Hours per BAS | Rate (illustrative) | Four BAS a year |
|---|---|---|---|
| Books reconciled weekly by owner, agent reviews and lodges | 1.5 | $110 | $660 |
| Books reconciled by bookkeeper each quarter, agent reviews | 3 | $110 | $1,320 |
| Agent has to reconcile and correct coding each quarter | 6 | $110 | $2,640 |
The difference between the first and third rows, $1,980 a year, is entirely the condition of the records. Compare it with the cost of setting up bank rules in the automation payback calculator, or estimate your own hours in the fee estimator.
Common BAS errors that create extra fees
- Claiming GST credits without a valid tax invoice for purchases over $82.50 including GST.
- Coding GST-free items as taxable, such as many basic foods, some medical supplies, or exported services.
- Including private expenses, which are not creditable.
- Bank fees and interest coded with GST; most are input taxed financial supplies with no GST.
- Double counting when receipt capture and bank feeds both create a transaction.
- PAYG withholding not matching STP. Since payroll is reported each pay run, the ATO can compare figures.
Correcting an error on a later BAS is possible within limits set by the ATO's correction rules; larger or older errors may need a revised BAS. Either way, the correction is usually billed.
What a BAS agent fee should include
When you get a quote, ask whether it covers:
- Review of the GST coding for the period, or only a check of totals.
- Reconciliation of PAYG withholding to payroll.
- Review of the PAYG instalment amount and advice on varying it.
- Lodgement and the payment reminder.
- Responding to ATO queries about that BAS.
A registered BAS agent can do all of this; see bookkeeper vs BAS agent vs tax agent.
What happens if you lodge late
The ATO can apply a failure to lodge on time penalty, calculated in penalty units for each 28 days the BAS is overdue, and the general interest charge on unpaid amounts, which since 1 July 2025 is not deductible. Lodging on time even when you cannot pay keeps the penalty off and opens payment plan options. See ATO late lodgement penalties and interest. Unpaid and unreported GST and PAYG withholding can also expose company directors to director penalty notices.
Frequently asked questions
Is it worth paying someone to do my BAS?
If your BAS includes payroll, fuel tax credits or many transactions, a registered agent often pays for themselves through fewer errors. A simple Simpler BAS from clean books may be quick to lodge yourself through software or Online services for business.
Can I switch from quarterly to monthly BAS?
Smaller businesses can generally elect to report monthly. Consider the extra fees: twelve lodgements cost more than four.
Do I need to lodge a BAS if I had no activity?
If you are registered for GST and have a BAS due, you generally still need to lodge it, even with nil amounts.
Does the BAS fee include GST?
If the agent is registered for GST, their fee includes GST, which you can usually claim as a credit on your next BAS.
Sources and where to check
- Australian Taxation Office — BAS due dates, Simpler BAS, GST accounting methods and correcting errors
- Tax Practitioners Board — check a BAS agent's registration
- business.gov.au — registering for GST and BAS basics
- Federal Register of Legislation — A New Tax System (Goods and Services Tax) Act 1999
