What’s the difference between an invoice, a receipt and an invoice-receipt?

An invoice is issued before payment, requesting payment from the buyer, while an invoice-receipt is issued after payment, confirming that the payment has been made and the transaction is settled.

The invoice-receipt combines the functions of both requesting payment (like an invoice) and confirming payment (like a receipt).

So, invoices are primarily used to request payment from the buyer and to establish a legal obligation for the buyer to pay the stated amount. When the customer pays, there's the need to issue the receipt, to mark the invoice as paid. How to issue a receipt?

Whereas an invoice-receipt serves as a proof of payment and acknowledgment of the transaction. It is issued by the seller to the buyer after the buyer has made the payment for the goods or services.