Cross Domain Tracking
Utm Tracking in Regpack System Fields
Regpack also tracks the URL that users began their registration journey, and can even pull out the UTM parameters in that URL if they exist. In order to view and report on this information, you'll need to create a report in Regpack and add those system fields to the report. You can set the report as "Info View" if you'd like to view this information in the user panel, or simply filter for the users you'd like this information on (like everyone who ordered a specific product) and then run the report.
As you can see above, you can view the UTM source, medium, campaign, as well as the full URL for every user.