The simplest and most accurate definition of an invoice is that it is a document that a seller gives a buyer to collect on a payment. It usually includes the cost of the goods or services rendered and outlines the mode and date of payment.
An invoice serves as a legal document and must contain specific details required for its validity. These include the names of the client, the terms of payment, a description of the goods or services delivered, and the cost.
An invoice serves as proof of a purchase made between you and your customer as a business entity.
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