Originally Posted by
drvannostren
Do some companies do that? Cuz "turning over" the mileage would require mileage transfers no?
Yes, some do. They may create an account for you, which you are required to use, and then they control how those miles are used. Or they can let you use your own account, but keep track of how many miles are "theirs" and make you use them for redemptions. No transfers involved.