Learning how to lodge a BAS properly takes about an hour the first time and ten minutes after that. The form itself is not complicated. What trips people up is knowing which labels apply, where the numbers come from, and what to do when a figure will not reconcile. This guide walks through the whole process, including the due dates, the common errors we correct every quarter, and the point at which a BAS agent saves you more than they cost.
What a BAS actually reports
A business activity statement reports the taxes you collected, withheld or owe for a period. Depending on your registration, that can include goods and services tax, PAYG withholding on wages, PAYG instalments on your own income, fringe benefits tax instalments and, in some industries, taxable payments annual reporting.
Not every business reports everything. A sole trader with no employees may only report GST. A company with staff will report GST and PAYG withholding. The labels on your form are generated by the ATO based on what you are registered for, which is why two businesses can have very different looking BAS documents.
Who has to lodge one
- Any business registered for GST. Registration is generally required once your GST turnover reaches $75,000, or $150,000 for a non-profit.
- Employers withholding PAYG from wages.
- Businesses and individuals paying PAYG instalments.
- Businesses registered for fringe benefits tax, or required to report taxable payments.
If you are not registered for GST and do not withhold wages, you may have no BAS obligation at all. That is worth confirming rather than assuming.
BAS due dates
| Reporting period | Quarter covered | Standard due date |
|---|---|---|
| Quarter 1 | 1 July to 30 September | 28 October |
| Quarter 2 | 1 October to 31 December | 28 February |
| Quarter 3 | 1 January to 31 March | 28 April |
| Quarter 4 | 1 April to 30 June | 28 July |
| Monthly | Each calendar month | 21st of the following month |
Two practical points from the ATO’s due dates guidance: if you lodge online you may be eligible for an extra two weeks, and quarter 2 already includes a one month extension. If a due date lands on a weekend or public holiday, you have until the next business day. Lodging through a registered agent can also move your date, which is one of the quieter benefits of having someone lodge for you.
Before you lodge: six checks
- Reconcile the bank. Every transaction in the period should be coded or deliberately excluded.
- Tie the GST to the ledger. Your GST collected and GST paid figures should match the reports, not just the bank balance.
- Check payroll. Wages, PAYG withheld and super must agree to your payroll reports and single touch payroll data.
- Review the previous BAS. Adjustments and corrections usually belong in the next period.
- Confirm the period. Lodging the wrong quarter is more common than it should be, especially in software.
- Check the bank account. A refund or payment direction that has changed will silently fail.
How to lodge a BAS, step by step
Option 1: Online services through myGov
Sign in with your myGovID, open ATO online services for business, go to the Lodgments tab and select Activity statements. Choose the period, enter each label, review the summary and submit. Save the receipt number. Your BAS is generally available about a week after the generation date, and most people receive an email 21 days before it is due.
Option 2: Straight from your accounting software
Xero, MYOB and similar platforms prepare the figures and lodge through a direct connection to the ATO. This is the fastest route and the least error prone, because the numbers come from the same ledger your bookkeeper reconciled. Our comparison of Xero and MYOB covers which suits which business.
Option 3: Through a BAS or tax agent
You send the records, the agent prepares and lodges, and you receive the figures and the receipt. Your lodgement date may be extended, and the agent carries the review work. For a business with payroll, mixed GST treatment or several entities, this is usually cheaper than doing it yourself badly.
The labels worth understanding
| Label | What it reports | Where the figure comes from |
|---|---|---|
| G1 | Total sales, GST inclusive | Sales in the ledger for the period |
| 1A | GST on sales | GST collected on taxable sales |
| 1B | GST on purchases | GST credits on business purchases |
| W1 | Total salary and wages | Payroll report, gross wages |
| W2 | PAYG withheld | Payroll report, tax withheld |
| T1 and T2 | PAYG instalments | ATO calculated instalment or your varied amount |
| 7A | Taxable payments annual report | Contractor payments, where the industry applies |
If a pre-printed amount appears at F1, G21, T2, T7 or 7A, check it before you change it. Those fields are sometimes locked for a reason.
Nil BAS and corrections
If you have nothing to report, you still need to lodge a nil BAS by the due date. In your online BAS, choose Prepare, then Prepare as nil. There is also an automated phone service on 13 72 26 available at any hour.
If you have already lodged and something is wrong, do not lodge a second BAS for the same period. Correct the error in the next activity statement, or revise the original if the error is material. If you are unsure which applies, ask before you act. A revised BAS is straightforward. An unreconciled duplicate is not.
The mistakes we see every quarter
- Claiming GST on private expenses, or on purchases with no valid tax invoice.
- Reporting wages paid to contractors who should have been treated as employees.
- Forgetting to include salary sacrifice in the correct payroll fields.
- Using cash figures rather than accrual figures, or the reverse, depending on your GST accounting basis.
- Missing the due date because the BAS was generated but no email was received.
- Lodging a nil statement when the bank account clearly shows trading activity.
Do sole traders need to lodge a BAS?
Only if registered for GST or withholding wages. Many sole traders are not registered and therefore have no BAS. Once turnover approaches the $75,000 threshold, registration becomes compulsory, and from that point the quarterly cycle begins. If you are close to the threshold, plan the registration date rather than being surprised by it.
Frequently asked questions
When and how do I lodge my BAS?
Quarterly if you are a standard GST registrant, with due dates of 28 October, 28 February, 28 April and 28 July. Lodge online through ATO online services, directly from your accounting software, or through a registered BAS or tax agent.
Can I lodge a BAS myself?
Yes. If your books are reconciled and your GST treatment is simple, lodging online takes minutes. Most businesses bring in an agent when payroll, mixed GST categories or multiple entities are involved.
What is a BAS statement and what is it used for?
It is the form that reports and pays your GST, PAYG withholding and PAYG instalments for a period. The ATO uses it to reconcile your business tax position across the year.
What happens if I lodge late?
Penalties and interest can apply, and repeated late lodgement increases the risk of ATO attention. If you cannot lodge on time, contact the ATO or your agent before the due date rather than after.
How do I lodge a nil BAS?
Open the BAS in online services, choose Prepare, then Prepare as nil, and submit. You can also use the automated phone service on 13 72 26.
Do I need a BAS agent?
Not legally. You need one if the time cost, the error cost or the lodgement extension is worth more to you than the fee. Our guide to BAS agents versus tax agents explains the difference in registration and scope.
Can I claim a BAS refund?
Yes, where GST credits exceed GST collected. The refund is paid to your nominated account. A pattern of large refunds with low sales is one of the signals the ATO reviews.
Get the quarter closed without the scramble
Most of the pain in BAS lodgement is upstream: unreconciled transactions, missing invoices, and payroll that was never checked. Fix the bookkeeping rhythm and the lodgement becomes routine.
Our reporting and bookkeeping service handles reconciliation, BAS preparation and lodgement, and the records that support them. If you would rather understand the process first, the ATO’s how to lodge your BAS page is the primary source, and our bookkeeping guide covers the records side.
BAS due and the books are behind?
We can reconcile the quarter, prepare the BAS and lodge it. You will know the figure before it is submitted.
Or call the office
973 Pacific Hwy, Pymble NSW 2073. Monday to Friday, 9am to 5pm.
