ePACT determines duplicates based on parent's actions. If they re-select an existing member, we assume this is a duplicate and we flag it and then simply prompt the parent to review and reconfirm the information.
For parents, they won't see any differences then if they were doing their annual reconfirmation. However, if they stop mid-way, their status will say Reconfirmation Required and the pending review will remain in their account.
Send them a reminder to prompt them to complete the Reconfirmation.