@phillip.higgins Thank you for posting in the Community and thank you @Humas1985 for chiming in!
@phillip.higgins You are unable to add this user to your account because a user already exists for this email address in a different lucid.app data residency region. Any given email address can only be used for one user across all data regions. For more information, please review the Data Residency article in our Help Center.
The user will need to change the email address of their current free US region accounts before you can add them to your data region account. They can do this in their Lucid account under their User Settings page. For more information please view this Help Center article. For a brief overview, check out this Community post. Once the email address on their account has been changed, they can go ahead and delete the free account. After this you should be able to add them to your account.
Hope this helps! Please let me know if you have any additional questions or concerns.