PURPOSE: To limit the dial origination of a storage element owner whose storage element is inserted into the key telephone system to a trunk line according to his or her set service class by stopping and permitting dial origination to the trunk line according to service class information corresponding to the name of the storage element inserted into the key telephone system.

CONSTITUTION: This device consists of key telephone sets 31-2m and a main device 10. For example, a magnetic card which is the storage element is inserted into the key telephone set 31, the number of the magnetic card is read by a magnetic card reader 11 and inputted to the central processing unit 8 in the main device 10. The central processing unit 8 obtains the service class information regarding dial origination corresponding to the magnetic card number inputted to a memory 9 and analyzes dial information to stop and permit the dial origination to the trunk line. Consequently, the dial origination of the storage element owner whose storage element is inserted into the key telephone set is limited according to the set service class.