I'm afraid we don't know too much abouyt the licensing side of things here. Best to contact Customer Service directly, they are open Monday to Friday at the link under Useful Links at the top of this page.
Contact them via online chat or telephone, it's free.
To speak with a Customer Service representative, call us at 020 79490107.
Estimated wait time: 10-30 minutes
Hours of Operation: 09.00-18.00 local, Monday through Friday
You can protect 15+ devices whatever that means, I would imagine anything in the list and I don't think a limit applies to any particular part, it could be 15 pcs or 1 pc and 14 tablets or phones or whatever.