การควบคุมภายในเกี่ยวกับรายได้ขององค์การโทรศัพท์แห่งประเทศไทย / ไพรวรรณ์ ตังสกุล = Internal control of revenue transactions of the telephone organization of Thailand / Paivan Tangskul
The Telephone Or0anization of Thailand is classified as large organization consisting of working units scattering in different locations. Close coordination among working units is therefore the topmost importance. The billing system and debts management which are directly related to revenue are clear indicators whether good coordination exists among working units. This is due to the fact that system has to rely greatly on the functioning of different units both inside and outside the Telephone Organization of Thailand. The concern of external working units such as commercial banks, the Communications Authority of Thailand, etc. as well as the behavior of subscribers in executing their payments are the major factors beyond the control of the Telephone Organization of Thailand. Therefore, in making the evaluation of the internal control of revenue transactions of the Telephone Organization of Thailand, it must take into consideration whether the existing internal control of the Telephone Organization of Thailand is functioning properly to protect damages which may occur and how well the occurred damages will be detected and amended. The said evaluation had been illustrated in the table listing relationships between possible errors and the control in each matter. In Considering such relationships, it can be concluded whether the reliability of the existing internal control in each matter is at low moderate, or, high level. The study revealed that billing is a voluminous work and should be on ongoing process. Then, if there were no portioning of periods in making billing in order that the volume of work will be distributed properly among concerned units, it would cause the dealy on billings which results in the occurrence of other problems. Hence, serious attention has to initially be given to this function and them corrective measures had to be provided to other in order to adjust the billing system for more flexibility and accuracy. However, the study revealed that the major part of the errors is due to the outstandings balance brought forward which is not updated after the bills had been paid and the errors are mostly within the system of the Telephone Organization of Thailand itself.