What Is an Invoice? Invoice vs Tax Invoice vs Receipt (Australia)

Short answer: An invoice is a document you give a customer to ask them to pay for goods or services you’ve supplied. A tax invoice is an invoice from a GST-registered business that carries the ATO’s required details, so a business customer can claim back the GST. A receipt confirms that you’ve been paid, and a quote is an offer made before any work starts. You must give a receipt for any purchase over $75, and if you’re registered for GST you must provide a tax invoice within 28 days when a customer asks for one on a sale over $82.50.

The definitions come from business.gov.au, the ATO and the ACCC, and they apply in the 2026–27 income year to sole traders, tradies and small businesses in Australia. This guide explains what each document is for and when you need it. For layouts you can copy, use the Australian invoice template, the receipt template and the quote template.

What is an invoice?

An invoice is a request for payment: it tells the customer what they owe, for what, and by when. It comes after you’ve supplied the goods or done the work, or a stage of it, and before you’re paid.

business.gov.au lists what a regular invoice should include:

• the word “invoice” and a unique invoice number
• your business name and ABN
• your contact details
• the date it was issued
• a description of what you sold, with quantity and price
• the buyer’s name or business name
• when and how you want to be paid.

One rule is firm. If you’re not registered for GST, you must use the word “invoice”, not “tax invoice”, and you must not show any GST. An invoice isn’t proof that you’ve been paid. It records what the customer owes until the money arrives.

What is the difference between an invoice and a tax invoice?

A tax invoice is an invoice that meets the ATO’s GST requirements. Only a business registered for GST can issue one. You must register for GST within 21 days of your GST turnover reaching $75,000.

	Invoice	Tax invoice
Who issues it	Any business, usually one not registered for GST	Only a GST-registered business
Heading	”Invoice”	Words showing it’s intended to be a tax invoice
GST shown	Never	Yes, or a statement that the total includes GST
Buyer’s details	Good practice	Required for sales of $1,000 or more
Lets the buyer claim a GST credit	No	Yes

Under the ATO’s tax invoice rules, a tax invoice for a sale under $1,000 must show seven things: that it’s intended to be a tax invoice, your identity, your ABN, the date, what you sold with quantity and price, the GST, and how much of each sale is taxable. From $1,000 the buyer’s identity or ABN is required too. In some industries the customer issues the tax invoice instead. That’s a recipient created tax invoice, and it needs a written agreement.

Why it matters to your customer: a GST-registered business generally can’t claim a GST credit on a purchase over $82.50 including GST until it holds a tax invoice.

What is the difference between a receipt and an invoice?

An invoice asks to be paid; a receipt confirms you’ve been paid. The invoice says what the customer owes, and the receipt shows that the debt has been settled.

business.gov.au says a receipt or proof of purchase must show your business name, your ABN or ACN, the date of supply, what you supplied and the price. You must give one for any purchase over $75. For anything smaller, you must give one within 7 days if the customer asks. A customer can also ask for an itemised bill for a service within 30 days of the bill, and you must provide it free within 7 days.

The two documents often merge. If you’re registered for GST and a customer pays on the spot, one “Tax invoice / receipt” can do both jobs, provided it carries every tax invoice detail. If you invoiced first, an invoice marked “PAID” with the payment date and method works as the receipt.

How is a quote different from an invoice?

A quote is an offer to do the work at a stated price, made before anything is supplied. An invoice asks for payment after it’s been supplied. business.gov.au says that if a customer accepts your quote, it becomes a legally binding contract. A quote isn’t a request for payment, and a business customer can’t claim GST from it.

Between the two sometimes sits a pro forma invoice: the expected charges set out like an invoice, often to collect a deposit, but not a tax invoice. Proforma invoice explains when to use one. How to put a quote together is covered in how to write a quote.

When is each document required?

Some of these documents are legal requirements; others are simply good practice.

Document	When you issue it	Is it required?
Quote	Before the work	No tax rule requires one; some state building laws require written contracts for home building work
Pro forma invoice	Before the sale is final	Never required
Invoice	After supplying, to ask for payment	No law requires one, but you need a record of every sale
Tax invoice	When you make a taxable sale, if registered for GST	Within 28 days if a customer asks, for sales over $82.50 incl. GST
Receipt	When you’re paid	Purchases over $75; smaller ones within 7 days if asked
Adjustment note	When a taxable sale is cancelled or its price changes	Within 28 days if asked, or of becoming aware, where a tax invoice was issued or requested

Most sole traders find it simplest to issue an invoice (or tax invoice) for every job and a receipt or “PAID” copy for every payment. That covers every rule in the table without anyone having to ask.

What if an invoice changes after you’ve sent it?

Don’t delete or rewrite it. Issue a credit note or, if you’re registered for GST, an adjustment note. Under the ATO’s ruling on adjustment notes (GSTR 2013/2), a GST adjustment arises when a taxable sale is cancelled or its price changes, for example when you refund a customer or give a discount after invoicing.

If you issued a tax invoice, or were asked for one, you must issue the adjustment note within 28 days of the earlier of the customer’s request or becoming aware of the adjustment. If you didn’t issue one and weren’t asked, you only need to issue an adjustment note if the customer requests one. Either way, the original invoice stays in your records and the adjustment note sits alongside it. The GST change goes on your BAS.

How do the documents fit together on one job?

Here’s one job from start to finish for a GST-registered electrician, Priya, installing outdoor lighting for a homeowner.

Date	Document	What it says
1 October 2026	Quote Q-052	Supply and install 6 garden lights, $2,000 + GST = $2,200, valid until 31 October
3 October 2026	(Customer accepts in writing)	The quote is now a binding contract
9 October 2026	Tax invoice INV-118	$2,200 including $200 GST, due in 7 days, quoting Q-052
14 October 2026	Receipt (INV-118 marked “PAID”)	$2,200 received by bank transfer on 14 October

The GST is 10% of $2,000, which is $200, or one-eleventh of $2,200. How to calculate GST has more examples. Because the customer is a homeowner, the quote shows the GST-inclusive total as the headline price. If Priya weren’t registered for GST, the quote, invoice and receipt would show one total with no GST, and the invoice would be headed “Invoice”.

Which documents do you need to keep, and for how long?

Keep a copy of every invoice, tax invoice, receipt and adjustment note you issue, and every tax invoice and receipt you receive, for 5 years. The period runs from when you prepared or obtained the record, or completed the transaction, whichever is later. Records must be in English or easily converted to English, and digital copies are fine.

The invoices you issue prove your income. The tax invoices and receipts you receive support your deductions and GST credits. Sole trader expenses and receipts covers the buying side.

…and where does Keel fit?

Keel: Invoice Maker & Receipts, by Ilura Technology OÜ, is an iPhone app for people who work for themselves, and it follows the same chain as the table above. You write an estimate, and when the customer accepts it, it becomes the invoice in one tap. Invoices are PDFs, and every quote, receipt, expense and invoice is kept under its job. A “who owes you” list shows what’s unpaid and drafts reminders that you review and send yourself; nothing is sent automatically. Records stay on the iPhone, with no account, no bank connection and no cloud sync, and the App Store privacy label reads “Data Not Collected”.

Keel is a record keeper. It doesn’t decide whether a document meets the ATO’s rules, lodge your BAS or connect to the ATO, so check your documents against the tables above. It’s free with no invoice limit, and free invoices carry a small “Made with Keel” footer. Keel Lifetime is a one-time purchase ($249.99 USD; the App Store shows your local price) that adds custom branding, a signature, premium templates and accountant-ready exports. Keel on the App Store. More Australian guides are on the Australia hub.

Frequently asked questions

What is an invoice in simple terms? An invoice is a bill you send a customer after supplying goods or services. It asks them to pay and says what for, how much and by when. It should show your business name, ABN, a unique invoice number, the date, a description with prices, the customer’s name and how to pay.

Is an invoice proof of payment? No. An invoice shows what a customer owes, not that they’ve paid. Proof of payment is a receipt, or the invoice marked “PAID” with the date and payment method. Your bank records back it up.

Is a receipt the same as a tax invoice? Not automatically. A receipt confirms payment, while a tax invoice is a GST-registered seller’s record of a sale that lets a business buyer claim GST credits. A receipt that includes every tax invoice detail, including the words showing it’s a tax invoice, can be both. That’s why many GST-registered sole traders use a combined “Tax invoice / receipt”.

Do I need to issue invoices if I’m not registered for GST? No law requires a non-GST business to issue invoices, but you need a record of every sale, and most customers won’t pay without one. Head it “Invoice”, never “Tax invoice”, and don’t show GST. Quote your ABN, because a business paying you more than $75 excluding GST without one generally has to withhold 47%.

Can an invoice be used as a receipt? Yes, once it’s paid. Mark the invoice “PAID” and add the payment date and method, and it shows every detail business.gov.au lists for a receipt: your business name, ABN, the date, what you supplied and the price. Send the customer a copy and keep one yourself.

Do I have to give a receipt for every sale? You must give one for any purchase over $75, and for smaller purchases within 7 days if the customer asks. The rule is the same for cash, card and bank transfer. Giving a receipt for every payment is simpler than tracking which ones you have to give.

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This article is general information, not tax advice. Consult a qualified Australian tax professional.