It depends what you mean by contract. I have one use year and I own at 4 resorts. They are all part of the same main contract, they just have number extentions to differentiate them, so I can transfer once for 2014, once for 2015, once for 2016, and so on. I could do the transfers on the same day if I wanted. In fact I have transferred out from 2 years of points on the same call to MS when I wasn't able to use them all.
If I were to buy a resale I would have a 'new' contract for that new group of points which would mean another transfer possibility.
Or I could buy another use year direct and have a separate contract with transferability.
Clear as mud?