The following extensions are not allowed to be used by any user.
Extension (range) | Reason |
|---|---|
0-99 | No extensions less than 3 digits |
311 | Local Community Hotline (where supported) |
411 | Local Directory Services (where supported) |
511 | Road Conditions (where supported) |
611 | Support Contact |
711 | TTY Relay Services (where supported) |
811 | Health Services (where supported) |
911 | Emergency Services |
988 | Mental Health and Suicide Hotline |
80000-89999 | Reserved for future use |
90000-99999 | System Features / Reserved Extensions |
Additionally, Any number that starts with 9, and only contains 9's and 1's. For example:
9911
991
9111