A Zenith number was a special type of telephone number in the United States which a subscriber could obtain, which was introduced prior to the development of toll-free service, which allowed a calling party to call the number's owner at no charge by dialing the operator and requesting the specified Zenith number. In some places the name Enterprise or the letters WX were used. Some organizations continue to keep their Zenith numbers (The California Highway Patrol continues to use the same single number it has for decades, Zenith 1-2000), but with the low cost of incoming WATS service, Zenith numbers have nearly disappeared. This article needs to be cleaned up to conform to a higher standard of quality. ... Subscriber: In a public switched telecommunications network such as the common telephone system, the ultimate user, customer, of a communications service. ... A toll-free telephone number (or Freephone number in the UK) is a special telephone number, in which the calling party is not charged for the call by the telephone operator. ... The person who (or device that) initiates a telephone call over the public switched telephone network is the calling party. ... The California Highway Patrol (CHP) is the state police force of California, originally a highway patrol agency created in 1929 to ensure road safety in California, it assumed greater responsibility as time went on. ... In U.S. telecommunications, a Wide Area Telephone Service (WATS) is a toll service offering for customer dial-type telecommunications between a given customer [user] station and stations within specified geographic rate areas employing a single access line between the customer [user] location and the serving central office. ...

The operator handled the call by looking up the regular number corresponding to the Zenith number, typically in a paper book kept at the switchboard, and completing the call as though it were a collect call to the regular number.

The reason the name Zenith was used is that the letter Z did not, at that time, appear on the telephone keypad, thus the only way one could call a 'Zenith' number was to dial Operator. A telephone operator at work on a private switchboard A telephone operator is either a person who provides assistance to a telephone caller, usually in the placing of operator assisted telephone calls such as calls from a pay phone, collect calls (called reversed-charge calls in the UK), calls which...