GST in Australia: the small business field guide

GST touches your prices, invoices, expenses and Business Activity Statement. Here is the practical version: when to register, what to charge, what you can claim and how to keep the numbers under control.

10%standard GST rate

$75kgeneral registration threshold

21 daysto register once required

What is GST?

Goods and Services Tax (GST) is a broad-based tax of 10% on most goods, services and other items sold or consumed in Australia. A GST-registered business generally adds GST to taxable sales, collects it from customers and sends the net amount to the Australian Taxation Office (ATO).

The word net matters. Registered businesses can generally claim credits for GST included in eligible business purchases. Your BAS works out the difference between GST collected on sales and GST credits claimed on purchases.

GST is not the same as income tax.

GST is collected through transactions and reported on a BAS. Income tax is calculated on taxable profit. Registration is based on GST turnover, not profit.

When do you need to register?

Most businesses and sole traders must register when their current or projected GST turnover reaches $75,000. For non-profit organisations, the threshold is generally $150,000. You usually need to register within 21 days of becoming required to do so.

Taxi and ride-sourcing drivers generally need to register regardless of turnover. Other special rules can also apply, so check your position with the ATO or a registered tax professional if your activities are unusual.

Below the threshold, registration is usually optional. Voluntary registration can make sense when your customers are GST-registered businesses or you have significant GST-bearing expenses, but it also adds BAS and record-keeping obligations.

The three types of GST sales

Taxable sales generally include 10% GST. Most ordinary goods and services fall into this category.
GST-free sales do not include GST, but the seller can generally still claim GST credits on related business purchases. Examples can include many basic foods, health services, education courses and exports.
Input-taxed sales do not include GST and generally do not allow credits for GST in related purchases. Examples can include financial supplies and residential rent.

Classification matters. Two sales with the same price can produce different GST outcomes, so confirm the treatment of anything that is not clearly an ordinary taxable sale.

How to calculate GST

To add GST to a GST-exclusive price, multiply by 10%. To find the GST inside a GST-inclusive price, divide the total by 11.

Price before GST: $220.00
GST at 10%: $22.00
Customer pays: $242.00

For a GST-inclusive sale of $242, the GST component is $242 ÷ 11 = $22. Your pricing and invoice settings should clearly distinguish between GST-inclusive and GST-exclusive amounts.

Claiming GST credits

You can generally claim a GST credit when your business is registered for GST, the purchase is used in carrying on the business, the price includes GST, you paid or are liable to pay for it, and you hold the required records.

Purchases above $82.50 including GST generally require a valid tax invoice before a GST credit can be claimed. If a purchase is partly private or relates partly to input-taxed sales, only the business or creditable portion may be claimable.

What belongs on a tax invoice?

A valid tax invoice needs enough information to identify the seller, show the seller's ABN, describe what was sold, state the date, show the price and make the GST treatment clear. Additional buyer details are generally required for sales of $1,000 or more.

Consistent invoice templates reduce errors. Make sure the words “Tax Invoice”, your ABN, line-item GST treatment and totals are clear, and keep corrections such as refunds or adjustments linked to the original transaction.

Set up GST rates in Gimbla

Use Gimbla's step-by-step guide to configure GST, VAT and sales tax rates for products, invoices, purchases and reporting.

Read the GST, VAT & Sales Tax guide

From transaction to BAS

Set the correct tax rate

Assign taxable, GST-free or input-taxed treatment when products, services and accounts are created.

Record every sale and purchase

Issue compliant invoices, capture supplier tax invoices and reconcile payments against the right transactions.

Review exceptions

Check mixed-use expenses, private portions, imports, exports, adjustments, refunds and any uncoded transactions.

Prepare and lodge the BAS

Confirm sales and purchase totals, compare them with your ledger and lodge by the applicable monthly, quarterly or annual due date.

Common GST mistakes

Waiting until after the registration threshold is crossed before monitoring GST turnover.
Charging GST before registration or forgetting to charge it after registration takes effect.
Claiming the full GST on purchases that include a private-use portion.
Treating all food, health, education or export sales as GST-free without checking the specific rules.
Claiming credits without a valid tax invoice or duplicating a credit after a bank-feed match.
Using GST collected as working capital and then facing a cash shortage when the BAS is due.

A simple GST routine

Keep GST manageable by reviewing transactions regularly instead of cleaning everything up at quarter end. Reconcile bank accounts, chase missing tax invoices, review tax codes and keep the expected BAS amount visible. A separate savings account for GST can also help protect the cash needed for lodgement.

GST rules can depend on the exact nature of a transaction. This guide provides general information, not tax advice. Refer to the ATO or a registered tax or BAS agent for advice about your circumstances.

Official GST resources

Thresholds and general rules were reviewed on 4 August 2026.

Ready to make GST part of your everyday accounting workflow?

Open the Gimbla GST Guide