My use year is March. If I borrow from 2017 to make a reservation for April 2016 but then I have to cancel, do those points go back to 2017 or do I have to use them in 2016? Thanks!
You cannot "unborrow" points. If you borrow 2017 UY points to make a reservation in your 2016 UY and then cancel that reservation, those borrowed points are stuck in your 2016 UY.
You cannot "unborrow" points. If you borrow 2017 UY points to make a reservation in your 2016 UY and then cancel that reservation, those borrowed points are stuck in your 2016 UY.
banking and borrowing are one way transactions and once done you can not undo and in case it isn't clear this means you can not then bank the borrowed points they have to be used in the UY they were borrowed into or they will be lost.