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Hi there, Thanks for reaching out! Unfortunately there isn't a way to change the domain in an active campaign. Part of the reason behind this would be the incongruency in the data presented if we did so. What you'll need to do in this case is create a new campaign. You can the archive the old campaign to preserve it's historic data. This way you can always reactivate it and pick up where you left off if needed. Hope this helps and have a great day!