This thread sort of freaked me out because I am actively closing on several units. (Westin KOR, KORN, Westin Flex, and SDO). I just called the center to ask this questions based on the thread. Moses, the rep I spoke to was pretty emphatic that adding a new unit to an existing account was not an issue and that the closing company should just use one of your contract numbers when submitting the paperwork. this is exactly how I have done it in the past. Perhaps there are other extenuating circumstances in the issue above and to be clear, I am not trying to merge accounts but rather add a new unit to an existing account. Also, all my units are vistana (not marriott) and also they have been both mandatory and voluntary units. The only "two account" issue I am aware of is when you try to use these units with Interval. Interval WILL make you set up two INTERVAL accounts (one for mandatory units/SVN) and one for the others. this has been true since the start. Also, the only time I have had issues is when the names were not spelled exactly the same and correctly. that can be a Deed issues, etc and gets messy but is really up to you to get right.