How to lodge your BAS online as a sole trader, step by step

Before you start

You need three things. First, a myGov account linked to the ATO; if you have ever done your own tax return online you already have this. Second, your ABN linked to your ATO account, which happens automatically for a sole trader because the ABN sits on your own tax file. Third, your BAS figures for the quarter.

For the figures, use your bookkeeping software or work through the bank statement. If you use FlowFi, open the BAS page for the quarter and it shows each label already filled in. Confirm the categories look right, especially anything flagged for review, and note the numbers.

Step 1: Log in and find the BAS

Sign in to myGov and select the ATO from your linked services. In ATO online services, go to the Tax menu, then Activity statements. You will see the current statement listed with its period and due date, and any earlier ones you have not lodged. Select the one you want to lodge.

The ATO app does the same thing on your phone. The menu names move around from time to time, so if you cannot see Activity statements, look under Tax or use the search box.

Step 2: Complete the GST labels

The form opens with the GST section. If you are on the simpler BAS, it asks for:

• G1 total sales for the quarter, including GST. Enter whole dollars.
• 1A GST on sales. For fully taxable sales this is G1 divided by 11, but if some sales were GST-free enter only the GST you actually collected.
• 1B GST on purchases. Only the GST on business purchases you can claim, and only the business portion of mixed expenses.

There is a question about whether you report GST-free sales or export sales; answer it as it applies to you. If the full form appears instead of the simpler one, you can generally still just complete G1, 1A and 1B and leave the detailed labels blank, but read the on-screen prompts.

Step 3: PAYG instalment, if you have one

If the ATO has entered you into PAYG instalments, the BAS will show either a pre-filled instalment amount (option 1, label T7) or ask you to apply an instalment rate to your income for the quarter (option 2, labels T1 and T2). Accept the pre-filled amount unless your income has changed enough that you want to vary it. Varying downwards carries a penalty risk if you underestimate, so keep it realistic. See PAYG instalments explained.

Step 4: Review and submit

The summary page shows the amount payable or refundable. Check that it matches what your software calculated. If 1B is larger than 1A you will see a refund, which the ATO pays into the bank account on file, so make sure that account is current.

Tick the declaration and submit. Save or screenshot the receipt number. That receipt, plus the report from your software, is your record that the BAS was lodged and what it contained.

Step 5: Pay

Payment is due on the same date as lodgement. The payment page shows your payment reference number (PRN), which is specific to you and stays the same for every BAS. Pay by BPAY from your bank, by card through the ATO’s payment gateway (a small card fee applies), or by bank transfer. Pay a day or two early so it clears by the due date.

If you cannot pay the full amount, lodge anyway. You can set up a payment plan in ATO online services for amounts under a certain threshold, usually without speaking to anyone. Interest applies, but lodging on time avoids the separate late-lodgement penalty.

Nil BAS and agents

If you had no sales and no purchases in the quarter, you still lodge, as a nil BAS. Enter zero in the labels and submit. It takes a minute.

If a registered BAS or tax agent lodges for you, they do it through their own system and you generally get extra time on three of the four quarters. FlowFi does not lodge on your behalf; it prepares the labels so you can lodge in a few minutes, or export the pack for your agent. Our lodge BAS page walks through the copy-across in more detail.