Who has to lodge a BAS in Australia?

You must lodge a BAS if you are registered for GST. You must register for GST when your GST turnover reaches $75,000 ($150,000 for not-for-profits), and immediately if you provide ride-sourcing or taxi travel services. Employers also lodge a BAS to report PAYG withholding from employee wages, and businesses that pay PAYG instalments (because their last income tax return showed business or investment income above the ATO threshold) lodge a BAS for those amounts.

How often do I need to lodge a BAS?

Lodgement frequency is set by the ATO based on your GST turnover. If your GST turnover is under $20 million you generally lodge quarterly; if it is $20 million or more you must lodge monthly (and you can elect monthly at lower turnovers). Businesses voluntarily registered for GST with turnover under $75,000 ($150,000 NFP) may be eligible to lodge an annual GST return instead.

Quarterly BAS due dates published by the ATO are 28 October (Q1), 28 February (Q2), 28 April (Q3) and 28 July (Q4). Lodging online or through a registered BAS agent typically gives you a longer lodgement window. Monthly BAS is due the 21st of the following month.

How does HelloBooks generate the BAS?

HelloBooks builds the BAS from your live ledger. Each transaction carries a Simpler BAS GST tax code, each pay run carries PAYG withholding amounts, and PAYG instalment income is computed from your business income accounts. When you open a BAS draft for the period, HelloBooks fills G1, G2, G3, G10, G11, 1A, 1B, W1, W2 and T1 from these ledger figures, and lists the underlying transactions for each label so you can drill in before lodging.

Does HelloBooks lodge the BAS to the ATO directly?

HelloBooks generates the completed BAS and exports it for lodgement through ATO Online Services for Business, the ATO Business Portal, or your registered BAS agent's lodgement software. You retain control over the lodge button. After lodgement you record the BAS payment in HelloBooks, which posts the journal that clears your GST liability and PAYG withholding accounts.

What is "Simpler BAS"?

Simpler BAS is a reduced GST reporting method the ATO introduced for small businesses with GST turnover under $10 million. Under Simpler BAS you only report G1 (total sales), 1A (GST on sales) and 1B (GST on purchases) — you do not need to report G2, G3, G10 or G11 separately. HelloBooks supports both Simpler BAS and full BAS reporting; the right method is selected per business based on registration.

Can I amend a BAS after I have lodged it?

Yes. The ATO allows you to revise a BAS within four years of the original lodgement for most businesses. In HelloBooks, edits to source transactions in a closed BAS period are flagged and surfaced when you next open the BAS, so you can decide whether to revise the lodged BAS or carry the adjustment to the next period (the ATO permits small adjustments below the correction limit to be carried forward).

How does HelloBooks handle GST-free, input-taxed and out-of-scope sales on the BAS?

HelloBooks ships with the standard Australian GST tax codes — GST 10%, GST-Free, Input Taxed, Out of Scope, Capital and Export — mapped to the correct BAS labels. GST-free sales flow into G3 (or G2 for exports), input-taxed sales (e.g. residential rent, financial supplies) flow into G4, and out-of-scope items are excluded from G1 entirely.

What if I find an error in last quarter's BAS?

Small GST errors can usually be corrected on a later activity statement under the ATO's correcting GST errors rules (subject to dollar and time limits). HelloBooks flags transactions edited in a closed period and includes them in the next BAS draft's exception list, so you can choose to revise the original BAS or carry the correction forward, and the audit trail remains intact either way.

Australia · BAS

Business Activity Statement (BAS) in Australia

A Business Activity Statement (BAS) is the form Australian businesses lodge with the Australian Taxation Office (ATO) to report and pay several obligations in one document — Goods and Services Tax (GST), Pay As You Go (PAYG) withholding, PAYG instalments, and other indirect taxes that apply to your business. HelloBooks generates the BAS directly from your live ledger, with every label tied back to the underlying transactions you can audit.

Last updated: 2026-05-09Last reviewed against ATO docs: 2026-05-09

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Who and how often

Who must lodge a BAS, and how often

You must lodge a BAS if you are registered for GST, if you withhold PAYG amounts from employee or contractor payments, or if the ATO has notified you that you are required to pay PAYG instalments. The lodgement frequency depends on your GST turnover and how the ATO has classified your business.

Quarterly BAS — GST turnover under $20 million (the typical small-business case).

Monthly BAS — GST turnover $20 million or more, or where you have elected monthly reporting.

Annual GST return — voluntarily GST-registered with turnover under $75,000 ($150,000 NFP) and eligible to elect annual reporting.

Source: ATO — Options for reporting and paying GST

HelloBooks BAS view — quarter selector, label totals and unreconciled-item exception list (illustrative; AU-specific capture pending).

What HelloBooks fills in

BAS labels generated from your ledger

HelloBooks pre-fills the BAS labels relevant to your registration. Simpler BAS users see G1, 1A and 1B; full BAS users see the additional G-codes and W-codes.

Total sales (incl. GST)

Export sales

Other GST-free sales

G10

Capital purchases (incl. GST)

G11

Non-capital purchases (incl. GST)

GST on sales

GST on purchases

Total salary, wages and other payments

Amount withheld from W1 (PAYG withholding)

PAYG instalment income

HelloBooks BAS draft with G1/1A/1B/W1/W2 pre-filled from the ledger

Draft BAS with each label totaled from the live ledger (illustrative; AU-specific capture pending).

How HelloBooks does this

From transaction to lodged BAS in four steps

1
Capture GST and PAYG at the source
Every sale, purchase, expense and pay run is tagged with the right GST tax code (GST, GST-Free, Input Taxed, Out of Scope) and PAYG withholding category at the moment it is recorded — not at quarter-end.
2
Open the BAS draft for the period
HelloBooks pre-fills G1, G2, G3, G10, G11, 1A, 1B, W1, W2 and T1 from the live ledger. You see each label, the underlying transaction list and any unreconciled items that would otherwise distort the numbers.
3
Resolve exceptions before lodging
Unreconciled bank lines, transactions missing a tax code, pay runs not posted and GST-free sales without justification are surfaced as a checklist. Each exception links back to the source record so you can fix it in place.
4
Lodge through the ATO and post the journal
Export the BAS or lodge through ATO Online Services for Business / your registered BAS agent portal. HelloBooks posts the BAS payment liability journal so the GST clearing accounts close to zero.

Related HelloBooks AU guides

ATO source documents

Reviewed against ato.gov.au on 2026-05-09.

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Business Activity Statement (BAS) in Australia

Who must lodge a BAS, and how often

BAS labels generated from your ledger

From transaction to lodged BAS in four steps

Capture GST and PAYG at the source

Open the BAS draft for the period

Resolve exceptions before lodging

Lodge through the ATO and post the journal

Related HelloBooks AU guides

ATO source documents

BAS questions answered

Ready to automate your books?

Business Activity Statement (BAS) in Australia

Who must lodge a BAS, and how often

BAS labels generated from your ledger

From transaction to lodged BAS in four steps

Capture GST and PAYG at the source

Open the BAS draft for the period

Resolve exceptions before lodging

Lodge through the ATO and post the journal

Related HelloBooks AU guides

ATO source documents

BAS questions answered

What is a Business Activity Statement (BAS)?

Who has to lodge a BAS in Australia?

How often do I need to lodge a BAS?

When is the BAS due?

How does HelloBooks generate the BAS?

Does HelloBooks lodge the BAS to the ATO directly?

What is "Simpler BAS"?

Can I amend a BAS after I have lodged it?

How does HelloBooks handle GST-free, input-taxed and out-of-scope sales on the BAS?

What if I find an error in last quarter's BAS?

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