What is a BAS, and what goes on it

What a BAS actually reports

A BAS is one statement that reports several obligations together, most commonly GST and PAYG withholding.

The Business Activity Statement is how the ATO collects reporting on more than one tax in a single form. For most small businesses the two big items are GST on sales and purchases, and PAYG withholding, which is the tax held back from employee wages.[^1] Depending on the business, a BAS can also include PAYG instalments, fringe benefits tax instalments, luxury car tax, wine equalisation tax, and fuel tax credits.[^1]

The ATO issues the BAS to you when you are registered. You report the figures for the period, and the form works out whether you owe the ATO money or are due a refund.

• GST collected on your sales, less GST paid on your purchases.
• PAYG withholding: tax held back from employee and some contractor payments.
• PAYG instalments toward your own expected income tax, where the ATO has entered you into instalments.
• Other items where they apply, such as fuel tax credits or fringe benefits tax instalments.

Who has to lodge one, and how often

If you are registered for GST you must lodge a BAS. Most small businesses lodge quarterly; some lodge monthly or annually depending on turnover and history.

GST registration is the trigger. Once the ATO records you as registered for GST, you are required to lodge a BAS for each reporting period, even if there is nothing to report for that period.[^2]

Quarterly is the most common cycle for small business. Larger businesses report monthly, and the ATO can direct a business onto monthly reporting where it has a history of non-compliance. As part of its 2025 "Getting it right" campaign, the ATO notified around 3,500 small businesses with a record of late or incorrect lodgement or non-payment that they would move from quarterly to monthly GST reporting from 1 April 2025, for a minimum of 12 months.[^3] The practical message is simple: keeping the books current through the quarter is far easier than rebuilding them the week before a deadline.

Who is legally allowed to lodge it for you

Preparing the underlying bookkeeping is open to anyone. Advising on your BAS and lodging it are BAS services that, when done for a fee, must be performed by a registered BAS agent or tax agent.

There is a legal line here that matters. The Tax Practitioners Board guidance is explicit that entering data, coding transactions, processing payments, and preparing bank reconciliations, whether done manually or through an automated process, are not BAS services because they do not require the interpretation or application of a BAS provision.[^4]

Working out your GST or PAYG position, advising on it, and lodging the BAS are BAS services. When provided for a fee or reward, they must be carried out by a registered BAS agent or tax agent.[^4] Any service offering fully automated BAS lodgement to Australian businesses is offering something the regulator has already restricted.

How to make BAS less painful

BAS feels heavy when bookkeeping is reactive. Keeping reconciliations, receipts, and questions current through the quarter turns lodgement into a review rather than a scramble.

Most of the pain owners feel at BAS time comes from catching up, not from the form itself. Receipts gathered late, transactions coded in a rush, and questions left until the deadline all pile into the same few days. Continuous bookkeeping spreads that work across the quarter so the figures are already in shape when the statement is due.