What to put on an Australian invoice.

Invoice or tax invoice? The distinction matters

These are not interchangeable words. A tax invoice is a specific document issued by a GST-registered business for a taxable sale, and it has legal content requirements. A regular invoice is simply a request for payment.

The practical rule: if you are registered for GST, you issue tax invoices. If you are not registered, you issue ordinary invoices, you do not charge GST, and you should not label the document a tax invoice. Getting this backwards causes real problems for your customer, because they may try to claim GST credits against a document that doesn't support it.

What a tax invoice must include

business.gov.au states that tax invoices must legally include:

• the words "tax invoice"
• your business name
• your Australian Business Number (ABN)
• the date you issue the invoice
• a short description of what you sold, including quantity and price
• the amount of GST payable (if any)

Sales over $1,000

For sales over $1,000 you must also include the buyer's identity or ABN. This is the single most commonly missed requirement, because most invoicing habits are formed on smaller jobs where it doesn't apply.

When you must issue one

If your business is registered for GST, business.gov.au says you must give a tax invoice when a taxable sale is more than $82.50 including GST, or when a customer asks for one within 28 days.

What's worth adding even though it isn't required

The legal minimum and a good invoice aren't the same thing. business.gov.au also suggests adding a unique invoice number, your contact details and your payment terms. In practice these are what actually get you paid:

• A unique invoice number. Without one, you cannot have a sensible conversation about which invoice is unpaid.
• Clear payment terms. "Payment due within 14 days" sets an expectation. "Thanks!" does not.
• How to pay. Bank details, or a payment link. Every extra step between reading the invoice and paying it adds days.
• The date the work was done. Especially useful for trades and services, where the invoice may arrive well after the job.
• A reference the customer recognises. A purchase order number, site address or job reference stops your invoice sitting in someone's queue unmatched.

GST registration

Whether you charge GST at all depends on whether you are registered. Registration is required once your business turnover reaches the ATO's registration threshold, and some activities require registration regardless of turnover. Rather than quote a figure that may change, check the current threshold and the rules for your situation directly with the ATO.

If you are not registered, you simply don't add GST — and your invoices are ordinary invoices, not tax invoices.

Why the ABN matters more than people think

An ABN is a required element of a tax invoice. Beyond that, quoting your ABN protects your cashflow: where an ABN is not quoted on an invoice, a business customer may be required to withhold an amount from the payment rather than pay you in full. That is a slow, annoying problem to unwind — and it is entirely avoidable by putting the number on the document.

A practical checklist

Before you send an invoice in Australia, check that it has:

1. The right label — "Tax invoice" only if you're GST-registered
2. Your business name and ABN
3. The issue date
4. A clear description of what you supplied, with quantity and price
5. The GST amount, if any
6. The buyer's identity or ABN, if the sale is over $1,000
7. A unique invoice number
8. Payment terms and how to pay

Doing this without thinking about it

The reason invoices go out with missing details is almost never ignorance — it's that they get written in a hurry, at the end of a long day, in a document template someone set up once. Using a tool that holds the structure means the fields are there whether you're concentrating or not.

ZappInvoice is built around that idea: quote, invoice, get paid and capture the expense in one place, so the paperwork is a by-product of doing the job rather than a separate task. It's particularly aimed at sole traders and tradies, who tend to be invoicing from a phone rather than a desk. See pricing.