It has to be the same UY AND titled the same way to add it to your current contract to function as one master contract. However, you can buy a different UY or have different owners listed if you want, it'll just function like contracts of two separate owners and the main way to combine points from each contract would be the same as if you and I wanted to do the same thing (transfers, separate but linked). The only exception is they tend to be more flexible on certain rules when it's multiple contracts of a single owner.