Hi @IBN
To assign caller ID policy to users, you could try to check the following steps below:
1) In Teams admin Center, go to Voice > Caller ID Policies. You could add the custom policy and rename the policy name from here. When you create the policy, click Save.
2)Click Users >Manage Users and choose the user you want to assign. Select policies and you could change the caller ID policy from global policy to your custom policy like the following picture:
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