Do I Need to Include GST on My Invoice?

You only need to include GST on your invoice if your business is registered for GST. If you are registered, add 10% GST to your taxable sales and issue a tax invoice that shows the GST amount. If you are not registered, you must not add GST: send a regular invoice with no GST line and without the words "Tax Invoice".

That one question, am I registered for GST, decides almost everything your invoice must show. The rest of this answer covers when registration is compulsory in Australia, what a valid tax invoice must include, which sales are GST-free, and the mistakes that cause problems at BAS time.

GST turnover is your gross business income, not your profit. Once you reach the threshold you have 21 days to register, and you need an ABN first. Below the threshold registration is optional. Some sole traders register voluntarily so they can claim GST credits on business purchases; if you do, every rule for registered businesses applies for as long as you stay registered.

Those are the ATO tax invoice requirements for a sale under $1,000. For a taxable sale of $1,000 or more, a compliant tax invoice must also show the buyer's identity or ABN. Your buyer needs this document to claim GST credits on their Business Activity Statement, so a missing field can hold up payment while they ask you to reissue it.

GST in Australia is 10%. On a GST-exclusive price, multiply by 1.1: a $500 job becomes $550, including $50 GST. If your prices already include GST, divide the total by 11 to find the GST component: $550 divided by 11 is $50. Most businesses show three lines at the bottom of the invoice:

1. Subtotal (excluding GST): $500.00
2. GST (10%): $50.00
3. Total price (including GST): $550.00

If you are not registered, issue a regular invoice instead. Include your business name, ABN, the date, a description of the work and the total, but leave out any GST line and never call it a tax invoice. Charging GST when you are not registered is not allowed: the amount is not yours to keep and the ATO can still require you to pay it. If your turnover is approaching $75,000, check it monthly; once you cross the threshold your invoices must change within the 21-day registration window.

When one invoice mixes taxable and GST-free items, your tax invoices must make clear which items include GST, for example by marking GST-free lines or showing GST only on the taxable subtotal. Input-taxed sales such as residential rent and many financial services also carry no GST, but you cannot claim input tax credits on the related purchases.

Quotes and deposits follow the same logic. If you are registered, quote GST-inclusive prices or state clearly that GST will be added, so the client is not surprised by the final bill. When you take a deposit, show GST on the deposit amount, and show GST only on the remaining balance when you bill the rest. Keep the wording consistent across quotes and invoices so the ATO requirements are met at every step.

E-invoicing is growing in Australia. Businesses that bill government agencies or large companies can send invoices through the Peppol network straight into the buyer's system. An e-invoice must carry the same details as a PDF, including your ABN and the GST amount, so switching format does not change what you must show.

If you are unsure whether an item is taxable, check the ATO's GST-free and input-taxed lists or ask your tax agent before you send the invoice. Fixing it afterwards needs an adjustment note, which means extra work for you and your client.

GST you collect is not income. Set aside the GST portion of every payment so it is ready when your BAS is due, otherwise quarterly GST can become a cash flow problem. Accounting software or an invoicing app that tracks GST on each invoice makes your tax obligations easier to meet, because the BAS figures come straight from your invoices instead of a spreadsheet.

InvoiceSonic lets you switch GST on or off for each invoice. With GST on, the invoice template adds 10% to taxable lines, labels the document "Tax Invoice" and shows the GST amount separately. With GST off, it produces a plain invoice with no GST line and the correct wording, so you never edit tax lines by hand.