An Australian Purchase Order (PO) is a formal commercial document issued by a buyer to a supplier that authorises the purchase of specified goods on agreed terms. It functions as a pre-contract offer: once the supplier accepts the PO — by signing, acknowledging, or beginning to fill the order — a binding contract is formed on the terms stated in the PO.

The Purchase Order is a cornerstone document in Australian business procurement. It establishes, in writing, exactly what the buyer wants, at what price, when, and where — before any goods change hands or any invoice is raised. This written record is essential for matching incoming invoices and delivery dockets to the original order, managing accounts payable, and preventing disputes over price, quantity, or specification.

Australian Purchase Orders operate within a framework of important legislation. The A New Tax System (Goods and Services Tax) Act 1999 (Cth) governs how GST of 10% applies to the supply: the PO must clearly identify whether prices are quoted exclusive of GST (with GST payable in addition) or inclusive of GST, and the supplier must issue a compliant tax invoice for the buyer to claim input tax credits. The Australian Consumer Law (ACL), which is Schedule 2 to the Competition and Consumer Act 2010 (Cth), imposes mandatory statutory guarantees on goods supplied in trade or commerce — including acceptable quality, fitness for purpose, and correspondence with description — that apply regardless of what the PO says and cannot be excluded by contract.

For businesses with regular procurement activity, using a standardised Purchase Order template ensures that every order is placed on consistent, legally sound terms that protect the buyer's interests and comply with Australian tax and consumer law obligations.

A Purchase Order is needed whenever a business in Australia purchases goods from a supplier and wants a formal written record of the transaction before delivery. The PO is particularly important in the following situations.

Regular procurement from suppliers. Businesses that regularly purchase stock, raw materials, equipment, or consumables from suppliers should use Purchase Orders to document each transaction. This creates a clear audit trail, supports internal approval processes, and simplifies invoice matching and payment authorisation.

Large or high-value orders. For significant purchases, a PO locks in the agreed price, quantity, and delivery date before the supplier begins production or dispatch. This prevents disputes about what was agreed and protects the buyer if the supplier attempts to vary the price or terms after the order is placed.

Purchases involving GST. A Purchase Order that clearly states prices exclusive of GST (with GST shown separately) and requires the supplier to issue a compliant tax invoice is essential for businesses that need to claim input tax credits under the GST Act.

Orders with specific quality or compliance requirements. Where goods must meet particular Australian Standards, safety requirements, or other specifications, the PO is the appropriate place to document those requirements and make them contractually binding on the supplier.

Suppressing supplier standard terms. Many suppliers attempt to supply goods on their own standard terms and conditions, which may be less favourable to the buyer. Issuing a clearly worded Purchase Order that expressly excludes or overrides the supplier's terms is the primary mechanism by which buyers can protect their position in the 'battle of the forms'.

Government and institutional procurement. Government departments and public institutions in Australia are typically required to raise a Purchase Order for any goods acquisition above a relatively low threshold. A compliant PO satisfies internal governance and audit requirements.

A well-drafted Australian Purchase Order should address several key elements to be effective as a procurement and legal document.

Unique PO number. Every Purchase Order should carry a unique reference number that is quoted on all tax invoices, delivery dockets, and correspondence. This number is the linchpin of the three-way matching process (PO — delivery docket — invoice) used by accounts payable departments to authorise payment.

Party identification with ABNs. Both the buyer and the supplier should be identified by their full legal names and Australian Business Numbers (ABNs). The supplier's ABN is required on the supplier's tax invoice for the buyer to claim an input tax credit for any GST paid.

Detailed item descriptions. Each line item should include a description, product code or part number (if applicable), quantity, unit of measure, and unit price exclusive of GST. Vague descriptions lead to delivery disputes; precise descriptions give the buyer a clear basis on which to reject non-conforming goods.

GST calculation. The PO should show the subtotal exclusive of GST, the GST amount (10% of the subtotal), and the GST-inclusive total. This assists the supplier in issuing a compliant tax invoice and assists the buyer in verifying the invoice against the PO.

Delivery details. The delivery address, required delivery date, and any special delivery instructions (such as delivery hours, contact person, or handling requirements) should be clearly specified. Time is frequently of the essence in commercial procurement, and a clearly stated required delivery date provides the basis for any claim arising from late delivery.

Payment terms. Standard Australian payment terms are 30 days from the date of a valid tax invoice. The PO should state the payment terms clearly so that the supplier can price accordingly and so that any late payment interest provisions in the supply agreement can be applied.

Quality and ACL compliance. The PO should confirm that goods must comply with the Australian Consumer Law statutory guarantees of acceptable quality and fitness for purpose, any specific Australian Standards, and all applicable laws. This reinforces the supplier's obligations and provides a contractual basis for rejection.

Governing law. The Australian state or territory whose laws govern the PO should be specified. This is particularly relevant if disputes arise, as state courts may be the appropriate forum.