500 Numbers

500 numbers are in the format 500-NXX-XXXX. 500 service is not portable; that is, the identity of the service provider is embedded in the number. The prefix (NXX) indicates the 500 service provider, and the line number (XXXX) indicates the particular premium service.

500-NXX codes, each subsuming a block of 10,000 numbers, are assigned to 500 service providers, who in turn assign individual numbers to their customers. Potential customers in search of a particular 500 number should view current assignments, find the NXX for the number they want, and contact the service provider listed to determine if the number they want is available.

500-NXX codes are assigned to 500 service providers according to the guidelines developed by the ATIS-sponsored Industry Numbering Committee. In time, additional NPA codes may be assigned for "follow me" personal communications services. Thus the assignment guidelines refer to the more generic "N00-NXX" rather than "500-NXX."

There is one special 500 area code . . . "555"

555 numbers are used to reach a wide variety of information services.  They are in the format 555-XXXX. The line number (XXXX) indicates the particular information service. 555 numbers are assigned according to guidelines developed by the ATIS-sponsored Industry Numbering Committee.

555 numbers may be assigned for either national or local use. A national assignment requires that the 555 number be implemented in at least 30% of all NPAs or states or provinces in the NANP Area. A local assignment is made for implementation in certain NPAs specified at assignment time.