@Mike-Rogger If you use the same customer account that Acid 7 is registered to, it should work. Be aware, an upgrade doesn't need Acid 7 to be installed. It's simply a full version sold with a price reduction.
I'm currently running ACID Pro 7.0 and I want to upgrade. Can I upgrade from 7.0 pro to either version of Acid 11 (Producer or Suite bundle)?
I would highly suggest you NOT to upgrade if you haven't already taken the bait. None of the versions released by Magix remained stable. All have issues and are a waste of money.