In telephony, a split plan is the practice of introducing a new area code by dividing an existing area code's territory and applying the new area code to one of the resulting divisions, replacing the existing area code within that section. Split plans are used as growth in demand for telephone numbers (due to the increase in use of pagers, fax machines, and cellular phones) required new area codes in increasingly densely populated areas. Unpopularity results from the fact that, after a split plan is implemented, the telephone numbers in an affected area are changed to a new area code, requiring printing of new stationery, advertisement, and signage, and the dissemination of new numbers to family, friends, and customers.
