How to fix the error "phone cannot be added" in Duo?


When enrolling an account in Duo MFA you will be prompted to enter your phone number. You may see this error message displayed if your phone is already enrolled and associated with another account.

###-###-#### 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.

Example of the error sequence:

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This dialog indicates you have enrolled with "Secure MFA" allowing you to have an extended password expiration date AND your phone number is already registered. Secure MFA blocks the ability to use Voice and SMS for device verification.

Secure MFA can be verified during the setup process if the "Phone number" option is not available on the "Select an options" screen.

Example: Secure MFA enabled. The "Phone number" option is NOT available.

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Example: Secure MFA NOT enabled. The "Phone number" option is available.

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Use the "I have a tablet" option to register your account with the existing phone. This will bypass the attempt to use Voice or SMS.

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Article ID: 1715
Thu 8/20/20 2:53 PM
Thu 3/21/24 5:19 PM

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