Personal Communications Services area codes
Area codes 500, 533, 544, 566 and 577 are non-geographic area codes reserved for personal communications services. The 500 code was authorized by the United States Federal Communications Commission, and introduced into the North American Numbering Plan in 1995.
In 1995 AT&T introduced a "follow-me" service under the brand name of AT&T True Connections using the 500 area code. It was designed to replace the AT&T EasyReach 700 service. Other local exchange carriers and interexchange carriers introduced similar competitive services.
AT&T True Connections service was not well received. Companies, hotels, and others with PBX equipment continued to block the dialing of 500 because it was a caller-paid number. Phone-sex services also began using the 500 prefix and forwarding the calls to various foreign countries.
The 500 prefix is still registered to a variety of phone companies, and is being used for non-geographic services including dial-up modem access.