Having a consistent numbering scheme for the extensions created within your PBX allows for easier turn-up and easier reference points when troubleshooting
For 3 digit Numbering
| Number Range | Feature/Function |
|---|---|
| 100-199 | Extensions |
| 200-299 | Extensions |
| 300-399 | Extensions |
| 400-499 | Call Queues / Hunt Groups |
| 500-599 | Call Queues / Hunt Groups |
| 600-699 | Conferences |
| 700-799 | Call Parks |
| 800-899 | Auto Attendants |
| 900-999 | Auto Attendants |
For 4 digit Numbering
| Number Range | Feature/Function |
|---|---|
| 1000-1999 | Extensions |
| 2000-2999 | Extensions |
| 3000-3999 | Extensions |
| 4000-4999 | Call Queues / Hunt Groups |
| 5000-5999 | Call Queues / Hunt Groups |
| 6000-6999 | Conferences |
| 7000-7999 | Call Parks |
| 8000-8999 | Auto Attendants |
| 9000-9999 | Auto Attendants |
System Reserved Extension Numbers
The following extension numbers can not be used and are reserved for system features. See Feature Codes (Star Codes) for a full list.
001-099, 411, 611, 911, 933, 988
Call Park range: 700-799 (7000-7999 for 4 digit numbering) is reserved for Call Parks. Don’t assign extensions in this range, but do create your call parks here.