How to invoice as a sole trader in Australia

A workable sole trader invoice carries five things: your name or trading name, your ABN, the date you issued it, a description of what you sold, and the amount payable. Only one of those, the ABN, is not required by law, and the section below covers why leaving it off still costs you. If you’re registered for GST, that document is a tax invoice and the ATO’s list of required fields is longer and specific. If you’re not registered, it’s a plain invoice, and it must not say “tax invoice” or show a GST amount.

Everything else - numbering, payment terms, how and when you send it - isn’t prescribed by law. It’s also where most of the money problems live.

General information, not tax advice. The ATO is the authority - see ato.gov.au or ask a registered tax or BAS agent.

What a sole trader invoice needs

A sole trader isn’t a separate legal entity from the person running it, so the invoice goes out under your own legal name or under a business name you’ve registered. Either is fine, as long as the customer can tell who they bought from and who they’re paying.

The fields that do the work:

Your identity. Your name or trading name, plus enough contact detail that a question about the invoice becomes an email to you rather than a reason to put it aside.

Your ABN. Not legally compulsory, but leaving it off has a direct consequence. Where a business pays another business more than $75 excluding GST for goods or services and no ABN is quoted, the payer generally has to withhold tax at the top rate, currently 47%, and send it to the ATO - see the ATO’s guidance on withholding from suppliers and its statement by a supplier page for the current rate. In practice what usually happens is simpler and just as annoying: the invoice stalls in someone’s accounts payable queue while they work out what to do with it. Your Australian business number is issued by the Australian Business Register, which is also where you apply for one.

The date you issued it. The date of issue is what payment terms are counted from. Show the date the work was done as well if the two are far apart.

A description of what was sold. Enough that the person approving the payment - frequently not the person who hired you - can recognise it without ringing you. “Consulting, June” invites a query. “Site survey and report, 12 June, as quoted Q-104” gets approved.

The amount payable and how to pay it. BSB, account number and account name exactly as your bank holds them, plus the reference you want used on the transfer.

Registered for GST or not: the one difference

This is the fork in the road, and it changes the document itself.

If you’re registered for GST, you issue tax invoices. The ATO’s tax invoices page sets out 7 details a tax invoice for a taxable sale under $1,000 has to contain clearly enough to be determined: that the document is intended to be a tax invoice, the seller’s identity, the seller’s ABN, the date of issue, a brief description of the items sold including quantity and price where relevant, the GST amount payable, and the extent to which each sale is taxable. Sales of $1,000 or more need one more field: the buyer’s identity or ABN. The full reference list is in what must legally be on an Australian tax invoice.

If you’re not registered, you don’t issue tax invoices at all. Head the document “Invoice”, show no GST line, and make the total the price. Charging GST while unregistered is a substantive problem, not a formatting one, and a customer who claims a GST credit off a document that shouldn’t have had GST on it will eventually have to unwind it.

Registration isn’t a choice once your GST turnover reaches the threshold. The ATO requires registration when GST turnover is $75,000 or more, and registration within 21 days of crossing it - the detail and the current figure are on the ATO’s registering for GST page.

Numbering and dates

Give every invoice a unique number and never reuse one. Sequential is the easiest scheme to defend and the easiest to spot gaps in: INV-0001, INV-0002, and so on. Some people prefix by year (2026-014) or by client, which is also fine. What doesn’t work is numbering by memory, or restarting at 1 each year without a prefix, because you end up with two documents called invoice 7.

The number matters more than it looks. It’s the reference in every subsequent conversation, it’s what the customer quotes on the bank transfer, and it’s how you find the invoice in three years when someone queries the job. “The one from March” is not a reference.

Two dates belong on the document: the issue date, and a specific due date. Not “payable on receipt”, not “14 days” on its own, but “Due 24 September 2026”. A date is something a person can put in a calendar and an accounts system can schedule. Anything vaguer resolves in favour of paying later.

When and how to send it

Send it the day the work is finished. Every day between finishing and invoicing is added to the front of your payment cycle, where it’s invisible, and a late invoice can miss a monthly payment run and arrive a month late rather than a few days late. On longer jobs, bill at agreed milestones instead of waiting for the end.

There’s one hard timing rule. If a customer asks you for a tax invoice, the ATO requires you to provide one within 28 days of the request, unless the sale is $82.50 including GST or less. That 28-day window sits on the same tax invoices page.

Email a PDF to whoever actually processes invoices, not just the person who hired you. Larger organisations often have a dedicated inbox, need a purchase order number, and run payments weekly or monthly. Asking “who do invoices go to, and do you need a PO?” during the quoting stage removes most administrative delay before it happens.

When it isn’t paid

Late payment is usually a process failure, not a personality one. A short, boring, repeatable sequence works better than waiting until you’re annoyed: a reminder a few days before the due date, a nudge the day after, a direct question about the payment date at a week overdue, a phone call at two weeks, and a formal letter at a month. The full sequence, including what to do about customers who are structurally slow, is in how to get invoices paid on time.

One thing worth deciding in advance: charging interest on an overdue account generally depends on the customer having accepted terms that provide for it, so it belongs in the quote rather than added to an invoice after the fact. A court or tribunal may separately award interest on a judgment, but that is a different thing from a term you can rely on yourself.

Keeping the record for five years

The ATO’s record keeping rules for business require most records to be kept for 5 years, generally counted from when the record was prepared or obtained, or the transaction completed, whichever is later. Digital copies are acceptable, provided they’re a true and clear reproduction and you can actually produce them.

That last part is the one that catches people. Five years is long enough for a laptop to die, a phone to be replaced, and a cloud service to change its export format. The test isn’t whether the files exist somewhere - it’s whether you could retrieve an invoice from four years ago this afternoon.

How Apsis helps

Apsis lays out the fields the ATO asks for, so an invoice can’t go out missing your ABN or the issue date, and it numbers invoices sequentially so you never have to remember where you were up to. You set the payment terms once and every invoice carries them. The invoice list shows what’s been paid and what’s still owed, flags each overdue invoice, and can be filtered by status and searched by number, title or client, which is the view you need when you’re deciding who to chase. Quotes, invoices and expenses with receipt uploads are all on the free plan, which covers 5 clients and 20 invoices a month, and they share the same client records, so an approved quote becomes an invoice without retyping anything.