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Error messages: SMS Address already in use or SMS Address is not an updateable field

Article: 000045177
Updated: April 18, 2026

What to do if you're trying to opt-into SMS communications and your phone number or email address is already in use

Constant Contact offers SMS services that enable organizations to communicate with their contacts via mobile devices. To receive messages from an organization that uses Constant Contact, you must opt in. The opt-in only allows the organization to contact you through the email address or phone number that you provided through the sign-up process. If you later try signing up with the same phone number or different email address, or different phone number and same email address, you can run into an error:

 

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This mobile number is being used with another email address

If you're seeing this error message when you're trying to sign up for SMS communications, it means you already signed up using the same mobile phone number and a different email address. If you want to continue signing up with a different email address, there are two options:

  • Update your profile information with the new email address - The Update Profile link is found in the footer of every email sent through Constant Contact and gives you a way to update the contact information you provided to the organization when you signed up. To update your profile, click the link in the email footer, then open the email that's sent through the organization to your old email address, and provide your new email address. Your contact profile is updated to include the new email address and text messages are sent to the same mobile number.

    Update profile in the email footer

  • Unsubscribe the old email address - The unsubscribe link is found in the footer of every email sent through Constant Contact. To unsubscribe, open an email sent from the organization to your old email address and click the "Unsubscribe" link in the footer at the bottom of the email. Next, visit the sign-up form for the organization and sign back up with the new email address and your mobile number.

    Unsubscribe in the email footer

 

We already have a mobile phone number for this email address

If you're seeing this error message when trying to sign up for SMS communications, it means you've already signed up with the same email address but a different phone number. If you want to continue signing up with a different phone number, there are two options:

  • Unsubscribe the old phone number - With the original phone that you used to initially subscribe to the organization's SMS communications, open the text thread for the organization, and reply "STOP" to unsubscribe. Then visit the organization's sign-up form and sign back up with the same email address and the new phone number. Your contact profile is updated to include the new email address and text messages are now delivered to your new phone number.
  • Sign up with the new phone number and a different email address - Visit the sign-up form for the organization and opt-in using your new phone number and a new email address. You will now receive text messages to both phone numbers until you're able to unsubscribe the old phone number (see instructions above).

    Sign up landing page with SMS opt in checkbox
     


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