Even in the customer has never had activity, there is more than one file in play. When you load a customer via VI, how many tables do you impact? There is the customer-master, contacts, Items, Ship-to address, Sales Tax Exemptions, and credit cards that I can think of off the top of my head. At best, you might orphan a record in a file. I agree with Wayne, they need to ride the horse they picked to the end of the trail. Otherwise, restore the backup, re-key the activity, and don't take chances.