Business Tax Australia Guide | GST, BAS, PAYG

Business tax in Australia usually comes down to keeping four workflows separate: income tax, GST, BAS, and PAYG. Income tax is based on taxable income. GST is collected and claimed if you are registered. BAS is the activity statement that reports obligations such as GST and PAYG. PAYG can mean either income-tax instalments or withholding from payments to workers, so the context matters (Business.gov.au - Income tax for business)(ATO - Business activity statements (BAS)).

This guide is for sole traders, side-hustlers, and small businesses that want a plain-English map before using the calculators. It is general information only, not tax or financial advice.

Quick summary

Business tax in Australia: the short version

Business.gov.au describes business income tax as being based on taxable income, calculated from assessable income less deductions (Business.gov.au - Income tax for business). That is separate from GST, which is generally not treated as ordinary business income because registered businesses collect it for the GST system.

For a sole trader, business profit flows into the individual tax return. For a company, the company is a separate taxpayer. The sole trader tax calculator is therefore the better tool for ABN holders operating in their own name, while company structures usually need accountant-led modelling.

GST: the invoice and transaction layer

GST is the 10% Goods and Services Tax applied to many goods and services in Australia (ATO — How GST works). If you are registered for GST, you generally charge GST on taxable sales and may claim GST credits on eligible business purchases.

Most businesses must register when GST turnover reaches $75,000 or more. Non-profit organisations have a higher threshold of $150,000, and some activities have special registration rules (ATO — How GST works).

Use the GST calculator when you need to add GST to a quote, remove GST from a receipt, or split a GST-inclusive total into GST and ex-GST components.

BAS: the quarterly reporting layer

A Business Activity Statement (BAS) is used to complete, lodge, and pay activity statement obligations such as GST and PAYG (ATO - Business activity statements (BAS)). For many small businesses, the practical BAS workflow is simple: collect the right totals, check labels like G1, 1A, and 1B, then lodge through the ATO channel that applies to the business.

The BAS calculator is the main business-tax tool on this site. It estimates GST on sales, GST credits on purchases, and the net GST payable or refundable for a BAS period.

If you want the step-by-step workflow, read the BAS lodgement guide.

PAYG: two different systems with similar names

PAYG can mean two different things.

PAYG instalments are income-tax prepayments. Business.gov.au explains that when business and investment income reaches a certain amount, income tax may be paid in instalments, usually quarterly, to reduce the final tax bill after the annual return is lodged (Business.gov.au - Income tax for business).

PAYG withholding is different. Employers generally withhold tax from wages and send those amounts to the ATO. Business.gov.au also notes withholding can apply to other workers under voluntary agreements and to businesses that do not quote an ABN (Business.gov.au - Income tax for business).

If you need employee withholding references, start with the PAYG tax table guide, then use the weekly tax table or fortnightly tax table for pay-cycle detail.

What to do each quarter

For a straightforward GST-registered small business, a practical quarterly routine is:

1. Export or total sales for the BAS period.
2. Separate taxable, GST-free, and input-taxed amounts where relevant.
3. Total GST collected on taxable sales.
4. Total GST credits on eligible business purchases.
5. Check whether PAYG instalment or PAYG withholding fields apply.
6. Compare the result with your accounting records before lodging.

Quarterly BAS due dates are generally tied to the end of each quarter, and the ATO due-date page should be checked for the actual date that applies to your statement (ATO — BAS due dates).

Where Property Tax Tools fits

The business-tax pages here are deliberately narrow. They are designed to help you check numbers before lodgement, understand what each label means, and keep GST/BAS/PAYG concepts separate.

They are not a replacement for accounting software, BAS agent services, or tax advice. If you have employees, multiple entities, unusual GST treatment, cross-border sales, or complex deductions, get advice before relying on a self-service spreadsheet or calculator.

For most users, the best path is:

1. Use the GST calculator for individual invoice amounts.
2. Use the BAS calculator for the BAS-period GST estimate.
3. Use the sole trader tax calculator for an annual income-tax estimate.
4. Keep records that make the next BAS or tax return easier to review.

Related tools

• BAS calculator - estimate GST payable or refundable for a BAS period.
• GST calculator - add or remove 10% GST from an amount.
• Sole trader tax calculator - estimate income tax, Medicare, HELP, and PAYG instalments.
• PAYG tax table guide - understand weekly, fortnightly, and monthly withholding references.