Question
Which three-digit extension numbers are reserbed and should not be assigned to users or services?
Applies To
- 8x8 Work
- 8x8 Contact Center
Answer
Three digit extension numbers that are reserved for 8x8 services and should not be assigned to any user or object. This includes, but not limited to, Ring Groups, Auto Attendants, etc.
We recommend using a minimum of 4-digit extension numbers for internal numbering plans. If this is not possible, and 3-digit extension numbers are required, avoid using any of the following extension numbers for internal numbering plans. Otherwise, issues may occur.
3-Digit Extensions
We recommend against using any of the following 3-digit combinations as extension numbers for internal numbering plans.
| 3-Digit Combinations | Description |
| 112 | Reserved for emergency services |
| 200 | Reserved |
| 400 to 443 | Reserved |
| 444 | Reserved for Auto Attendant |
| 445 to 499 | Reserved |
| 500 | Reserved for Voicemail |
| 501 to 699 | Reserved |
| 711 | Reserved |
| 800 | Reserved |
| 900 to 999 | Reserved |
4-Digit Extensions
We also recommend against using any of the following 4-digit combinations as extension numbers for internal numbering plans.
| 4-Digit Combinations | Description |
| 2000 | Reserved for Ring Group |
6-Digit Extensions
We also recommend against using any of the following 6-digit combinations as extension numbers for internal numbering plans.
| 6-Digit Combinations | Description |
| 90000 to 91999 | Reserved |