| 411 | Information |
| 611 | Customer Service |
| 911 | Emergency |
| 933 | 911 Test Number |
| 700-799 | Used for Dynamic Call Parking Queues |
| 7000-7999 | These are unusable as 4-digit extension numbers because they conflict with the 7+extension (3 digit extension) rule to transfer a call directly to voicemail. |
| 70000-79999 | These are unusable as extension numbers because they conflict with the 7+extension (4 digit extensions) rule to transfer a call directly to voicemail. |
| 99XXX+ | 99 plus a users extension (3 and 4 digits) are reserved to work with Intercom features. |
| 5000 | Unregistered Login to VMail (prompted for acct no and password) |
| 5001 | Registered Login to VMail (prompted for password only) |
| 5002 | Hot Desking Sign In |
| 5003 | Requests the User's PIN then provides a 2nd dialtone (useful for calling from phones in public spaces |
| 5004 | Reserved for Future Hot Desking Development. |
| 8888 | This User has a limited view in the PBX portal. When assigned the Office manager role, the 8888 User can only view the Home and Call History pages. Other Office manager functions are hidden. |
| XX | Please use 3 and 4 digit extensions. 2 digit extensions will cause setup issues. NOTE: Extensions should not begin with the number 0. |
