Here are things I know to be true:
1. After MVW acquired Vistana, all the Vistana properties switched their operations to the Marriott reservations system (MARSHA), which is old and decrepit but MVW is apparently married to it. Reservations in this system have an eight digit confirmation number. Properties no longer have access to the Vistana reservations system.
2. However, owners still make reservations and reserve their weeks using the old Vistana reservations system, perhaps because it already incorporates all the idiosyncrasies of VSN and its rules and policies, which it might be hard to incorporate into the creaky old Marriott system. The Vistana system uses six digit confirmation numbers.
3. After you make a reservation (on the Vistana system), somebody at MVW manually creates a matching reservation on the Marriott system. Because this is done manually, typos and other errors can occur so it’s important for owners to carefully check both the Vistana and Marriott confirmation emails they should receive.
4. In rare instances, a property may have trouble locating a reservation by name, so it is highly advisable to have both the six and eight digit confirmation numbers just in case there is trouble finding your reservation. I have never encountered this problem, despite checking in to Vistana properties 4-8 times per year, but apparently some have. It seems like this problem may be more likely to occur when the guest name has been changed, such as on an ownership reservation that has been gifted or rented, so your guests should definitely have those confirmation numbers available to save themselves any grief.
5. In the vast majority of cases, confirmation numbers are NOT necessary at check in, but they are an insurance policy you don’t want to need (and not have.)
