How to lodge your BAS yourself (sole traders and small business)

Yes, you can lodge your BAS yourself. You work out the figures from your books, then lodge and pay online in the ATO's own services, no agent needed. Here's what it is, when it's due, what you need and how to do it.

What is a BAS?Link to this section

A BAS (business activity statement) is the form you send the ATO to report and pay some of your business taxes. For most small businesses that means:

• GST, the 10% tax on most things you sell. You report the GST you charged customers and the GST you paid on business purchases. The difference is what you pay, or what you get back.
• PAYG withholding, the tax you take out of your staff's pay, if you have employees.
• PAYG instalments, prepayments of your own income tax, if the ATO has put you on them.

The ATO's How to lodge your BAS (opens in a new tab) page has the full list.

Who has to lodge a BAS?Link to this section

If your business is registered for GST, you lodge a BAS. You have to register for GST once your GST turnover reaches $75,000 a year, and you can choose to register below that. The ATO's registering for GST (opens in a new tab) page explains how turnover is worked out.

Not registered for GST and no staff? You might not get a BAS at all, unless the ATO has set you up for PAYG instalments.

Had a quiet quarter? You still lodge. A BAS with nothing to report is a "nil" BAS, and it's due on the same date as any other.

When is my BAS due?Link to this section

Most small businesses lodge quarterly. These are the ATO's standard dates for this financial year, one BAS for each quarter:

1. Q1Jul to SeptDue 28 October 2026
2. Q2Oct to DecDue 28 February 2027
3. Q3Jan to MarDue 28 April 2027
4. Q4Apr to JunDue 28 July 2027

If you lodge online you may get an extra 2 weeks for quarters 1, 3 and 4. Quarter 2 already has a longer deadline, so it doesn't get the extra time. A due date on a weekend or public holiday moves to the next business day.

Businesses with GST turnover of $20 million or more lodge monthly, due on the 21st of the next month. Some smaller businesses choose monthly too.

Your BAS shows its own due date, and that's the one that counts. The ATO's due dates page (opens in a new tab) has the detail, and our BAS due dates tool shows your next one.

What do I need before I start?Link to this section

The BAS itself is short. The work is having your books up to date first.

• Your sales and GST on sales. Total sales (label G1) and the GST you charged (1A).
• GST on your purchases. The GST you paid on business costs (1B), backed by tax invoices.
• Wages and tax withheld, if you pay staff. Gross wages (W1) and the tax you held back (W2), from your payroll.
• Your PAYG instalment, if you have one. The ATO usually works out the amount for you.

Two things trip people up. First, reconcile your bank account, so every sale and every expense is in. Second, know whether you report GST on a cash basis (when money changes hands) or accrual basis (when you invoice or get billed). It changes which sales land in which quarter.

Selling through Shopify, Square or PayPal? Your deposits have fees taken out, so they aren't your sales. Our guide to recording payouts and their fees walks through it.

How do I lodge my BAS online?Link to this section

You lodge in the ATO's own online services. There are two, depending on how your business is set up.

• Sole traders can use Online services for individuals and sole traders. You get to it through myGov, with your myGov account linked to the ATO.
• Companies, trusts and partnerships (and sole traders who prefer it) use Online services for business. You sign in with a Digital ID, such as myID.

Once you're in, look for your activity statements in the lodgments area. If you can't spot it, search the ATO site for "lodge your BAS online". Menus change, so we won't send you clicking through theirs.

Open the statement for the right period and type in your figures. The ATO adds up the totals and shows what you owe or what's coming back. Check that amount matches what you worked out, then lodge. You'll get a receipt number. Write it down or keep a screenshot.

Nothing to report? The online statement has an option to prepare it as nil.

The ATO's online services page (opens in a new tab) has help signing in.

How do I pay my BAS?Link to this section

Pay by the due date to avoid the general interest charge. The ATO accepts BPAY, card and other methods, listed on its how to pay page (opens in a new tab). Most need your payment reference number (PRN), which is on your statement.

If you can't pay in full, talk to the ATO before the due date. If you owe $200,000 or less, you may be able to set up a payment plan yourself in online services.

What records should I keep?Link to this section

Keep the invoices, receipts, bank statements and workings behind each BAS. The ATO says to keep most business records for 5 years (opens in a new tab). Digital copies are fine.

Also keep a note of what you lodged and when, and when you paid. That's handy if you ever need to fix a BAS later.

How does Billbook help?Link to this section

Billbook works out your BAS from your books, so the figures are ready when you are. GST and BAS are on the Free plan.

BAS, Jul to Sep

$2,521.00$2,521.00

Here's how a quarter goes:

The step by step is in our help docs: do your BAS.

When should I get an accountant or BAS agent?Link to this section

Doing your own BAS is very doable when your business is simple. Get help when:

• You're not sure what's GST free, input taxed or private use
• You've got staff, fuel tax credits or FBT (fringe benefits tax) in the mix
• You've made a mistake on an earlier BAS and need to fix it
• You're behind on lodging or can't pay

A registered agent may also get you more time to lodge. You can find one on the Tax Practitioners Board register. And if they use Billbook Practice, they see the same books you do.

More free helpLink to this section

Try the GST calculator and the rest of our free tools, or see what Billbook does.