Sometimes rebates or deductions are allowed to purchasers. This may be done because the goods are not satisfactory and are returned, or the price is higher than the purchaser had expected, or for some other reason. The seller will make out and send to the purchaser a memorandum of credit, which shows how much credit or reduction he will be allowed. It differs from the invoice in that it shows a credit instead of a debit. Credit memorandums are usually printed in red.