Which document initiates payment obligations?

• A. A receipt confirming payment has been made.
• B. A purchase order requesting goods from a supplier.
• C. An invoice formally requests payment from a customer.
• D. A delivery note listing items delivered.

Answer: (C)

A payment obligation is created when a request for payment is issued. An invoice is the document that formally requests payment from a customer, listing the amount due, the goods or services provided, and the due date. This makes the customer legally responsible for paying by the agreed terms.

Receipts prove that payment has already been made, not that payment is due. A purchase order is a request to procure goods or services, initiating the buying process but not the act of owing money. A delivery note records what was delivered and in what quantity; it relates to logistics, not to the obligation to pay.