PURPOSE: To temporarily limit an origination only to a specific extension according to the intention of a subscriber by changing an extension class to a line wire origination disable made only when personal identification numbers coincide with each other or releasing the mode.

CONSTITUTION: When an extension subscriber A dials a specific number for setting an individual transmission limit and his own identification number, dialed numeric information is received by a register 3 and transferred to a central control unit 4 every time. The contral control unit refers the identification number of the subscriber stored in a main memory device 5 to the dialed identification number, when the identification numbers coincide with each other, the present extension class of the subscriber A is stored in the separate area of the main memory device 5 according to the specific number, thereafter, the extension class is changed to a long distance origination disable class and a request completion sound is sent to the subscriber A. Consequently, the long distance origination from the extension subscriber A is adjusted until this setting is released.