central office prefix
Telecommunications
The first three digits (N) of the seven-digit telephone number assigned to a customer's telephone exchange service when dialed on a local basis. [NECA/FCC] Synonym [loosely] prefix.
The first three digits (N) of the seven-digit telephone number assigned to a customer's telephone exchange service when dialed on a local basis. [NECA/FCC] Synonym [loosely] prefix.