Configuring Unassigned Number Ranges

02 May 2024

This guide covers the configurable behaviour when calls are made to unassigned numbers in Microsoft Teams.

In this article

Introduction

This guide is intended for customers who are looking to utilise the feature of routing calls to unassigned numbers in Microsoft Teams through the Teams Admin Center (TAC).

Up to date information from Microsoft regarding this feature can be found here: https://learn.microsoft.com/en-us/microsoftteams/routing-calls-to-unassigned-numbers

Routing rules for unassigned numbers

Create and manage rules to specify how to route unassigned phone numbers. Calls to unassigned numbers are matched against routing rules using match patterns in the evaluation order you specify. When a match is found, the call will be routed based on the matched rule.

Creating Rules

  1. Navigate to the Teams Admin Center (TAC) https://admin.teams.microsoft.com/dashboard
  2. Choose “Phone Numbers” from the left-hand menu under “Voice”
  3. Choose the “Routing rules” tab to add a new rule
  4. Press “Add” to add a new rule
  5. A side bar will open where you can fill in the information and choose the rule type you require.
  6. These rule selections will change how numbers are chosen
    1. Advanced Setup - You can enter a regular expression to match the numbers for this rule
    2. Number starting or ending with
    3. Phone number range – You can enter a range of numbers in full E164 format to match for this rule
    4. Single number – You can enter one single number in full E164 format to match for this rule
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  7. Once you have chosen your “condition match” then you will need to choose the destination
  8. These routing options will change what happens when a user calls a number matching the rules above.
    1. Greeting – Upload a pre-recorded file that will play then disconnect the call
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    2. Person in organization – Search for a voice enabled user in the organization 
    3. Voice Application – Search for a Resource Account assigned to Voice Application
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  9. Press “Save” at the bottom of the sidebar

Testing your Rules

You can test the rules that you have created in the Teams Admin Center as well.

  1. Navigate to the Teams Admin Center (TAC) https://admin.teams.microsoft.com/dashboard
  2. Choose “Phone Numbers” from the left-hand menu under “Voice”
  3. Choose the “Routing rules” tab
  4. Choose “Test Number”
  5. Enter the number you would like to test in full E164 format and press “Test”
  6. If a test is complete, you will receive the below message with the rule name it was matched too

Using unassigned rules to block outbound numbers tenant wide.

Microsoft have stated on their documentation page that “There are no other checks of the numbers in the range. If the range contains a valid external phone number, outbound calls from Microsoft Teams to that phone number will be routed according to the treatment.”.

This means number ranges can be blocked tenant wide and will be picked up by the rules even if they are not in Microsoft Teams for user assignment.

For example, if you would like to create a rule to block all outbound calls to premium rate numbers in Spain this can be done by creating a rule as such:

  • unassigned numbers