You can update your Email/Quicken ID at any time. Your email address is used as your Quicken ID.
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Choose Edit menu
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→ Preferences.
In the left pane, select Quicken ID & Cloud Accounts.
In the right pane, under Quicken Profile, select Update Profile.
The My Account screen displays.
Select Change Email/Quicken ID.
Enter your new email address for the Email/Quicken ID.
Enter your Current Password.
Click Save Changes.