Interest, which is known as the rent of money, is one of the most important processes of business life. Throughout history, interest has maintained its importance. People have made money transactions with interest since the known date. It has even been instrumental in the emergence of various fights and even wars. The most common procedure in interest transactions is undoubtedly discount transactions. Throughout the history, discount transactions were discussed. It has been applied in various ways. Sometimes they are subjected to regular and sometimes random processes. The discount can be encountered in a simple case, as well as in the case of compound discount. The compound discount can be applied in two types: internal discount and compound external discount. The compound internal discount is available in each book. However, there are negative sentences about the applicability of the compound outer seal. However, the composite external discount is also applicable. In this study, the applicability of the compound external discount, which should be done if the nominal value documents such as long-term bonds, checks are paid in person, have been investigated. It is alleged that compound exemptions can not be applied in studies on external discounts in existing works. In this study, a theorem on compound external discounting is developed, and this theorem is tried to show applicability on equivalents.