If you trade as a company, your invoice must clearly display your company name and ACN. There is one exception: you can use your ABN instead, but only if the last nine digits of your ABN match your ACN. This is a small detail many businesses overlook, but it is essential to stay compliant.
When you are GST registered, every invoice you issue must be labelled “Tax Invoice”. If the total amount is under $1,000, your invoice needs to include the words “Tax invoice”, your business name, ABN, the issue date, a description of the goods or services, the GST amount (or the phrase “Total price includes GST”), and an indication of which items are taxable. For invoices of $1,000 or more, the same information applies but you must also include the buyer’s identity or ABN. If you are not GST registered, you should label the document simply as “Invoice” and never charge GST.
Invoices are considered incorrect when they fail to meet these requirements. Common mistakes include using “Tax Invoice” without being GST registered, leaving out your ABN or ACN, failing to include buyer details on invoices over $1,000, or showing GST incorrectly. In the construction industry, another frequent error is missing the mandatory Security of Payment wording or, for head contractors, the required Supporting Statement. These errors can delay payment or even make the invoice invalid.
There are several steps to check off before issuing an invoice. Make sure your legal name, ABN, and ACN are up to date, and confirm whether you are GST registered. Record your client’s details, confirm the contract scope, and agree on any variations and supply dates. You should always include payment terms and bank details, note any retention amounts if applicable, and remember that invoices and records must be kept for five years. In construction work, you must also add the Security of Payment statement and the Supporting Statement if you are a head contractor. Taking these steps ensures your invoice will be accepted without dispute.
If you use subcontractors, their invoices must always include an ABN. If a subbie cannot provide an ABN and has not completed a valid Statement by a Supplier, you may be required to withhold tax at the top marginal rate before paying them. As a head contractor you also have the responsibility of confirming, through the Supporting Statement, that you have paid all subcontractors any amounts due. This step is not optional and can expose you to penalties if ignored.
A simple template helps make sure nothing is missed. For amounts under $1,000, a standard tax invoice should include the label “Tax invoice”, your name, ABN (and ACN if you are a company), invoice number, issue date, customer name, description of goods or services, the GST line or statement “Total price includes GST”, the total payable, and payment terms. For invoices of $1,000 or more, all of this applies plus the buyer’s identity or ABN. In NSW construction, you must also add the wording “This is a payment claim made under the Building and Construction Industry Security of Payment Act 1999 (NSW)”, and if you are a head contractor, attach the required Supporting Statement.
For businesses just starting out, free software can make invoicing easier without extra costs. Zoho Invoice is a strong option with unlimited clients and automation features. Square Invoices allows you to send invoices and accept card payments on a pay-as-you-go basis. Invoice Ninja is another flexible choice, offering both free hosted and open-source versions. These tools are practical for freelancers and small operators.
If your business needs deeper accounting functions, there are strong paid options available. Xero is widely used in Australia and integrates bank feeds, BAS, payroll, and eInvoicing. QuickBooks Online also offers BAS support, expense tracking, and mobile access. MYOB Business provides strong local support and flexible plans with invoicing and payroll options. Investing in paid software can save time, reduce errors, and provide compliance peace of mind.
The most important rules to remember are simple. Use “Tax Invoice” only if you are GST registered. Always include the buyer’s identity on invoices of $1,000 or more. If you operate as a company, show your ACN or ABN. In construction, never forget to add the Security of Payment wording and a Supporting Statement if you are a head contractor. Finally, consider using eInvoicing through the Peppol network, which is becoming increasingly common in Australia and makes payments faster and safer.
