Invoice, receipt and payment voucher: what is the difference?
Three documents that often get confused, and which one fits which situation.
These three documents get mixed up because in everyday speech people call them all "the invoice". But they answer three different questions, and using the wrong one can leave the recipient unable to record the expense.
An invoice answers: what was sold, how much, at what price. It is evidence about GOODS. It lists items, quantities and unit prices. It says nothing about whether money has moved.
A receipt answers: has the money been received. It is evidence about PAYMENT. It may not list goods at all - just the amount and what it was for.
A payment voucher is the recipient's internal record. It goes into their own cash book, and usually carries the payer's signature so it can be checked later.
The most common confusion: an invoice does not replace a receipt, and a receipt does not replace an invoice. An invoice without a receipt proves a sale but not payment. A receipt without an invoice proves payment but not what it was for.
The tidiest approach for a small shop is to combine them on one sheet: list the goods, state the payment status, and leave room for a signature. One sheet that covers all three jobs means three fewer things to file.
If the customer is a business, ask what documentation they need before you issue anything. Asking one question up front is far cheaper than reissuing and collecting a signature again.