conference call services

A vertical service code or VSC is a special telephone number that usually begins with the * (star) key on the touch tone keypad. Most codes are two digits, although those starting with 2 or 3 are now usually three digits. Some cellular telephone companies also use # instead of *, though this is actually just a short number typically used for other commercial services (e. g. pizza delivery), and not a VSC for accessing telephone company services. In some cases VSCs can be accessed from rotary phones by dialing 11 instead of the *.

Vertical service codes are often colloquially referred to as "CLASS" codes, after the AT&T trademark for the original implementation of these codes, known as "Custom Local Area Signalling Service". Phone, Web Conferencing, Webinar and Webcasting Services.

List of vertical service codes

The following are the VSCs generally used in the North American Numbering Plan. Not all of these services are available in all areas, and some are only available to landline or cellular telephones. Some require additional services be purchased from the telephone company to use them.