premium-rate telephone number

Etymology
In the original, phone numbers beginning with an area code of 800 were reserved for so called toll-free numbers, where the party receiving the call pays the charges. The telephone companies later developed a corresponding set of numbers beginning with the area code 900, which would permit the owner of the number to receive additional fees from the caller.

Noun

 * 1) A telephone number for which an extra charge is assessed to the caller, part of which is returned to the owner of the number.