A fax receipt is another name for a confirmation page.
At the end of a fax transmission, the sending fax machine waits for a signal from the receiving fax machine to say “transfer complete.”
When the sending fax machine receives this signal, it prints out a fax receipt to show proof of receipt.
The fax receipt typically includes the date and time the transmission started and finished, as well sending and receiving information. There may be copies of the first page or multiple pages in the sent fax. These features vary by fax machine manufacturer.