How to Lodge Your BAS Online (Step by Step)
You lodge your BAS online by signing in to ATO Online services for business with your myID, opening the activity statement under Lodgments, filling in the GST labels (plus PAYG labels if you have staff or pay instalments), pressing Lodge and paying by BPAY or direct debit. It takes about 15 minutes once your bookkeeping is up to date, and lodging online yourself earns an automatic two-week extension on three of the four quarters. Here's what happens on each screen, what goes in each label, how to pay, and what to do when you make a mistake or have nothing to report.
If you're still working out what a BAS is or whether you need GST registration at all, start with our plain-English GST and BAS guide.
The three ways to lodge online
| Method | Best for | How you sign in |
|---|---|---|
| ATO Online services for business | Companies, partnerships, trusts, and sole traders who want the full business view | myID app, linked to your ABN in Relationship Authorisation Manager (RAM) |
| ATO online services through myGov | Sole traders only | myGov account linked to the ATO |
| SBR-enabled accounting software (Xero, MYOB, QuickBooks and others) | Anyone whose books are already in software | Lodge from inside the program once it's connected to the ATO |
All three count as lodging online, so all three qualify for the two-week concession. Lodging from your software is the least error-prone because the figures flow from your coded transactions, but it needs every transaction reconciled first. This guide follows the Online services for business path: it's free, it works whatever software you use, and the labels are identical wherever you lodge.
Step 1: Set up myID and link your business
This is the step that catches first-timers, so do it a week before the due date, not the night before.
- Download the myID app (the Australian Government's Digital ID app, formerly myGovID) and verify your identity. As at September 2026, myID is the only Digital ID accepted for ATO online services, and you need at least a Standard identity strength to link a business as its principal authority.
- Link your ABN in Relationship Authorisation Manager (RAM). The principal authority — the sole trader, a company director or a partner — logs in to RAM with their myID and links the business. To let a bookkeeper or staff member lodge for you, authorise them in RAM; they use their own myID.
- Sign in to Online services for business with your myID. First time in, check the Profile section so your contact details and the bank account for refunds are current.
Sole traders can skip RAM and use myGov instead: sign in, select the ATO, then Tax, Lodgments, Activity statements. Everything below applies the same way.
Step 2: Open the activity statement
Select Lodgments, then Activity statements. Statements are listed by period with their due date and status, and appear a few weeks before each period ends. Open the one you're lodging and note the document identification number (DIN) at the top; you'll need it if you ever lodge by phone.
Have three things beside you: your accounting software's GST report for exactly the same period, your payroll report showing gross wages and tax withheld (if you have employees), and last quarter's lodged BAS to sanity-check against.
Step 3: Fill in the GST labels (Simpler BAS)
If your GST turnover is under $10 million (as at September 2026) you're on Simpler BAS, the small-business default, which means only three GST labels:
| Label | What it means | What to enter |
|---|---|---|
| G1 Total sales | Gross sales for the period | All sales including GST, GST-free and input-taxed sales; answer "yes" to the question asking whether G1 includes GST |
| 1A GST on sales | GST you collected | The GST component of your taxable sales — 1/11th of the GST-inclusive taxable amount |
| 1B GST on purchases | GST you paid | GST on business purchases you hold a valid tax invoice for |
Your GST position is 1A minus 1B. Positive means you owe the ATO; negative means a refund to the bank account in your profile.
Two mistakes dominate here. G1 should include GST-free sales (a cafe's fresh-food sales, say) but not BAS-excluded items like wages, loan repayments or drawings. And 1B only covers purchases with GST in the price, so bank fees, interest, ASIC fees and stamp duty don't belong there even though they're real expenses. Our guide to GST-free versus BAS-excluded codes sorts out which is which. Enter whole dollars only; the system won't take cents.
Step 4: PAYG withholding (W1, W2, W5)
If you withhold tax from employees' pay, the PAYG tax withheld section appears on your statement. Small withholders report and pay quarterly on the BAS; medium withholders report monthly on an instalment activity statement, with the quarterly BAS picking up the GST. The ATO tells you your cycle when you register for withholding.
| Label | What to enter |
|---|---|
| W1 Total salary, wages and other payments | Gross payments to employees before tax, including allowances and leave loading |
| W2 Amount withheld from payments at W1 | The tax you withheld from those wages |
| W5 Total amounts withheld | W2 + W3 + W4; carries to label 4 in the summary |
If you report through Single Touch Payroll, the ATO has pre-filled W1 and W2 on quarterly statements since the July–September 2023 quarter. Check the pre-filled figures against your payroll report rather than accepting them: they're only as good as the pay events you lodged, and a missed or duplicated pay run shows up here.
Step 5: PAYG instalments and how to vary them
If the ATO has put you on PAYG instalments (prepayments towards your income tax), you'll see one of two layouts:
- Instalment amount (T7). The ATO has worked out a dollar figure from your last return. Accept it and it flows to 5A.
- Instalment rate (T1 and T2). Enter your instalment income for the quarter at T1 (gross business and investment income, excluding GST); the pre-printed rate at T2 applies to it and the result lands at 5A.
If business has dropped and the ATO's figure is too high, you can vary it: enter your revised amount or rate, choose a reason code at T4 (a fall in income, for instance) and the varied figure replaces 5A. Two rules keep you safe. The variation must be lodged by the due date, and the total of your varied instalments for the year must reach at least 85% of the tax you actually end up owing — fall short and the ATO can charge interest on the shortfall. Varying is legitimate; lowballing to help cash flow is not.
If you only receive an instalment notice with no GST section, there's nothing to lodge unless you're varying. Just pay by the date on the notice.
Step 6: Check the summary and lodge
The summary nets GST (1A minus 1B), PAYG withholding (label 4) and your instalment (5A) into one figure. Before you select Lodge:
- Compare 1A, 1B and W2 with last quarter. A number that has doubled or halved needs explaining before you lodge, not after.
- Check the sign. If your GST report says refund but the summary says payable, you've probably swapped 1A and 1B.
- Read the declaration. You're signing that the statement is true and correct, and you carry that responsibility even if a bookkeeper prepared the figures.
On lodging you get a receipt ID. Save the PDF or at least note the ID. The amount owing appears under Accounts and payments within a day or two.
Step 7: Pay what you owe
Lodging and paying are separate, and the due date applies to both.
- BPAY — biller code 75556, with your payment reference number (PRN) in the reference field. The PRN is on the statement and under Accounts and payments, then Payment options. BPAY can take up to four business days to reach the ATO, so pay early.
- Direct debit — set it up in Online services for business as you lodge. You pick the date and the ATO takes the money.
- Card — accepted through the ATO's online payment service, but a card payment fee applies.
- Payment plan — if you genuinely can't pay in full, you can set one up yourself online for debts up to $200,000 (as at September 2026), provided your lodgements are up to date.
Any unpaid balance accrues the general interest charge, compounding daily at a rate above 11% a year (as at September 2026), and since 1 July 2025 it's no longer tax deductible. Lodging on time even when you can't pay stops the late-lodgement penalty and keeps the payment-plan door open.
Lodging a nil BAS
Registered for GST but had no sales, purchases or wages in the period? You still lodge. Open the statement, enter 0 at G1, 1A and 1B (and W1/W2 if shown), lodge. Or call the ATO's automated line on 13 72 26, 24 hours a day, with your ABN and the DIN ready; it takes up to three statements per call.
Skipped nil statements are a leading cause of penalties for dormant businesses. If you've stopped trading for good, cancelling your GST registration is the cleaner fix.
Fixing a mistake after you've lodged
A duplicated invoice, a missed supplier bill, GST claimed on the stamp duty inside an insurance premium — everyone does it eventually. You have two options.
Revise the original statement. In Online services for business, open the lodged statement's history and select revise. The ATO recalculates and you pay or receive the difference. Use this for large errors or anything outside the limits below.
Correct it on your next BAS. Simpler for small errors, but the rules depend on which way the error went (as at September 2026):
| Type of error | Limits for correcting on a later BAS (GST turnover under $20 million) |
|---|---|
| Debit error — you paid too little GST (understated 1A or overstated 1B) | Net debit errors under $12,500, corrected within 18 months of the original due date, and not the result of recklessness |
| Credit error — you paid too much GST | No dollar limit; correct within the four-year period of review for the original statement |
To correct on a later BAS, just adjust the relevant label — add the missed GST to 1A or the missed credit to 1B — and keep a note of what you changed and why. Errors outside the limits must go through a revision of the original period.
Deadlines and the online two-week concession
Lodging yourself online pushes the standard quarterly date out by two weeks on quarters 1, 3 and 4. For 2026-27:
| Quarter | Standard due date | Due if you lodge online yourself |
|---|---|---|
| Jul–Sep 2026 | 28 Oct 2026 | 11 Nov 2026 |
| Oct–Dec 2026 | 28 Feb 2027 (effectively Mon 1 Mar) | No extra time — already extended for everyone |
| Jan–Mar 2027 | 28 Apr 2027 | 12 May 2027 |
| Apr–Jun 2027 | 28 Jul 2027 | 11 Aug 2027 |
Monthly statements are due on the 21st of the following month with no concession. A registered agent adds another two weeks on top of the online dates, which is one reason people hire a bookkeeper or BAS agent even when they could lodge themselves. Every date, including monthly ones, is in our BAS due dates guide.
Miss the date and the failure-to-lodge penalty for a small business is one penalty unit — $364 — for every 28 days or part thereof, capped at five units or $1,820 (as at September 2026). The ATO often remits a first offence if you ask, but it's a conversation you'd rather avoid.
Key takeaways
- Set up myID and link your ABN in RAM well before your first due date; sole traders can lodge through myGov instead.
- Under Simpler BAS you complete only G1, 1A and 1B for GST; add W1, W2 and W5 if you pay staff, and check any STP pre-fill against your payroll report.
- Vary a PAYG instalment by the due date and keep the year's total to at least 85% of your final tax, or expect interest on the shortfall.
- Pay by BPAY (biller code 75556, PRN as the reference) or set up direct debit when you lodge; allow up to four business days for BPAY.
- A nil BAS still has to be lodged — online with zeros, or on 13 72 26.
- Lodging online yourself gives you until 11 November, 12 May and 11 August for quarters 1, 3 and 4 in 2026-27; late lodgement costs $364 per 28 days, capped at $1,820.
Where to get help
- ATO — Business activity statements (ato.gov.au): label instructions, correcting GST errors, varying instalments.
- ATO — Online services for business (ato.gov.au/online-services): setting up myID and RAM, access troubleshooting.
- myID and RAM support (myid.gov.au and info.authorisationmanager.gov.au): identity strength, linking a business, authorising staff.
- ATO business enquiries on 13 28 66; automated nil lodgement on 13 72 26.
- A registered BAS agent or tax agent (check the register at tpb.gov.au) if your BAS involves instalments, mixed GST codes or a correction you're not confident about.
Frequently asked questions
How do I lodge my BAS online myself?
Sign in to ATO Online services for business with your myID (or ATO online services through myGov if you're a sole trader), go to Lodgments then Activity statements, open the statement for the period, fill in G1, 1A and 1B for GST plus W1 and W2 if you have staff, check the summary and select Lodge. You get a receipt ID straight away and the amount owing appears on your account.
Do I get extra time if I lodge my BAS online?
Yes. Lodging a quarterly BAS yourself through Online services for business, myGov or SBR-enabled accounting software gives you an automatic extra two weeks on quarters 1, 3 and 4, so for 2026-27 the dates become 11 November, 12 May and 11 August. The October–December quarter is already extended to 28 February for everyone and gets nothing extra, and monthly BAS don't get the concession.
Do I still have to lodge a BAS if I had no sales?
Yes. If you're registered for GST you must lodge every activity statement even when there's nothing to report, otherwise it shows as overdue and the failure-to-lodge penalty clock starts. Lodge a nil BAS online by entering zero at each label, or through the ATO's automated phone service on 13 72 26, which runs 24 hours a day and takes up to three statements per call.
How do I fix a mistake on a BAS I've already lodged?
Either revise the lodged statement in Online services for business or correct the error on your next BAS. If the mistake meant you paid too little GST and your turnover is under $20 million, you can fix it on a later BAS provided the net total is under $12,500 and it's within 18 months of the original due date (as at September 2026). If you paid too much, you can correct it on any BAS within the four-year review period.
How do I pay my BAS after lodging?
The quickest options are BPAY (biller code 75556 with the payment reference number shown on your statement) or a direct debit set up in Online services for business when you lodge. Card payments attract a fee, and BPAY can take up to four business days to reach the ATO, so don't leave it until the due date.
General information only. This guide doesn't take your personal or business circumstances into account and isn't financial, legal or tax advice. Rates and thresholds change — check the official sources linked in this guide and get qualified advice where your circumstances require it.