800 number

A toll-free telephone number or freephone number is a telephone number that is billed for all arriving calls instead of incurring charges to the originating telephone subscriber. For the calling party, a call to a toll-free number from a landline is free of charge.

A toll-free, Freecall, Freephone, 800, 0800 or 1-800 number is identified by a dialing prefix similar to a geographic area code, such as 800. The specific service access numbers vary by country.

The features of toll-free services have evolved as telephone networks have moved from electro-mechanical call switching to fully computerized stored program controlled networks.

Originally, a call billed to the called party had to be placed through a telephone company operator as a collect call. The operator had to secure acceptance of the charges at the remote number before manually completing the call.

A few large businesses and government offices received large numbers of collect calls, which proved time consuming for operators.

Prior to the development of automated toll-free service many telephone companies provided a manual version of caller free service.

Examples of operator-assisted toll-free calling include the Zenith number introduced in the 1950s in the U.S. and Canada, as well as the original manual 'Freephone' service introduced by the British Post Office in 1960.

Both systems were similar in concept. The calling party would ring the operator (now '100' in the UK, '0' in Canada/U.S.) and ask for a specific free number. In the U.S., the caller would ask for a number like "Zenith 1-2345" (some areas used "Enterprise" or "WX" instead of "Zenith", but in the same pattern of a free service name and a five-digit number). In the UK, the caller would ask the operator to ring "Freephone" and a name or number (such as "Freephone Crimebusters" to pass on tips about a crime to the constabulary).

In either case, the operator would look up the corresponding geographic number from a list and place the call with charges reversed.

A Zenith number was typically available from a predefined area, anything from a few nearby cities to a province or state, and was listed in local directories in each community from which the subscriber was willing to accept the charges for inbound calls.

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Wikipedia