Which of the following is typically included on a sales invoice?

• A. Invoice number
• B. Customer password
• C. Delivery schedule
• D. Insurance policy

Answer: (A)

An invoice needs to be uniquely identifiable so both sides can track and reference the transaction. The number assigned to an invoice provides that unique reference, helping with recording, matching payments, and creating an audit trail. While invoices often show date, seller and buyer details, a description of goods or services, quantities, prices, totals, and payment terms, the defining item among the options is the invoice number. The other options aren’t typical parts of a sales invoice: a customer password would be a security detail and isn’t included on invoices; a delivery schedule is usually found on a packing slip or delivery note, not the invoice itself; and an insurance policy has no relevance to the invoicing document.