GST on trade invoices — the basics
When to charge GST, what an ATO-compliant Tax Invoice has to include, and what to do about ABNs.
GST is one of those things you sort once and never think about — until you get audited, or until a client's bookkeeper asks why your invoice is missing something. Here's the practical rundown for trade and field service operators in Australia.
When you have to register for GST
You must register for GST if your business's annual GST turnover is $75,000 or more (or projected to be). For taxi and ride-share drivers it's from the first dollar. Many operators choose to register voluntarily below the threshold to claim back GST credits on equipment and consumables.
What an ATO-compliant Tax Invoice has to include
If your sale is over $82.50 (incl. GST) and you're registered, your invoice must be a Tax Invoice. The ATO requires:
- The words “Tax Invoice” displayed clearly
- Your business name and ABN
- The date of issue
- A brief description of what was supplied (item, quantity, price)
- The GST amount payable (or a statement that the total includes GST)
- The total amount payable
For invoices over $1,000 (incl. GST), you also need to include the buyer's name or ABN.
Inclusive vs exclusive pricing
You can show prices as either GST-inclusive or GST-exclusive — but the invoice has to make it clear which one. The two standard formats:
- Inclusive:Show the total as GST-inclusive, and state “Total includes $X GST”.
- Exclusive: Show subtotal ex GST, then a separate GST line, then the total. This is the cleaner format for itemised quotes and what most B2B clients prefer.
What to do about ABNs
Always show your ABN on your invoice. If a customer is a business and you don't supply an ABN, they're required to withhold 47% of the invoice amount as PAYG and remit it to the ATO. You don't want that to happen.
For larger invoices, ask for the customer's ABN too — it helps cleaner reconciliation on their end.
BAS, frequency, and what to keep
Once registered, you lodge a Business Activity Statement (BAS) — most small operators do this quarterly. You report GST collected on your sales and GST you paid on purchases (input tax credits), and pay the net to the ATO.
Keep invoices, receipts, and bank records for at least five years. Most accounting software handles this automatically as long as you're consistent about coding transactions.
Common mistakes
- Charging GST without being registered — you'd have to pay it to the ATO without being able to claim credits. Big problem.
- Forgetting to update prices when GST is added after registration — existing quotes don't magically include it.
- Issuing “invoices” that don't meet Tax Invoice requirements — the customer can't claim the GST credit, and you may not have valid sales documentation if audited.
How Bizzie handles it
Every Bizzie invoice is generated as an ATO-compliant Tax Invoice with your ABN, the “Tax Invoice” heading, line-item GST, and the right totals. You set whether prices are entered inclusive or exclusive of GST; the maths is done for you on every line.
This guide is general information only and not tax advice. For your specific situation, talk to a registered tax agent or accountant.