terminal apparatus having a telephone function stores a correlation relationship between a prefix number of a first n digits of a telephone number decided based on a numbering plan and a total number of digits for a telephone number decided based on a numbering plan , for a plurality of types of numbering plans . in the event that a user starts to input a telephone number , the terminal apparatus refers to a correlation relationship of prefix numbers and a total number of digits for the telephone number , selects a prefix number matching with the number inputted by the user , acquires the total number of digits corresponding to the selected prefix number , and in the event that the number of digits for the number inputted by the user matches the acquired total number of digits , determines that input of the telephone number is complete and carries out call processing .