Duo: Phone Number Cannot Be Added

Issue/Question

Why do I see Error [Phone Number] cannot be added, if you entered this phone number by mistake, go back and re-enter it, Otherwise, Contact your administrator to add this phone?
 

Environment

• Duo

Cause

The mobile number is already attached to another Duo user.

Resolution

1.  Please contact the Service Desk with the following information: 
   1. Email address
   2. Phone number you are trying to register to Duo