900 number

Origin: In the original North American Numbering Plan, 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. Origin information sourced from Wiktionary contributors (CC BY-SA 4.0).