What Is Invoice?

An invoice is a document a business sends to a customer to request payment for goods or services. It lists what was supplied, the price, and how the customer should pay. Invoices are the foundation of business cash flow and form an essential part of bookkeeping and tax records.

Every invoice should answer four basic questions:

  • Who is sending it? — your business name, ABN, and contact details
  • Who is it for? — the client's name and billing address
  • What is being charged? — itemised list of products or services with prices
  • How and when should it be paid? — due date, payment methods, and bank details

In Australia, businesses registered for GST must issue a "tax invoice" rather than a regular invoice for sales over $82.50 (GST inclusive). Invoices can be created in word processors, accounting software, or with a dedicated tool like InvoiceSonic. The key is consistency, accurate numbering, and quick delivery — the faster you invoice, the faster you get paid.

Ready to create your first invoice? Use InvoiceSonic's free invoice generator and get a professional PDF in under 2 minutes.

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