Originally Posted by
DFWsakp
I have never seen the hotels caring about it.
At times when I have gone out on family vacations with other family friends, I have put my Marriott# on the checkout and nobody ever has had any issue about it. They don't have much status with Marriott and rarely travel and so never care about the points, while for me the points are a nice icing on the cake.
Your scenario is different because you aren't taking advantage of lounge and other benefits in that case, and there was no Marriott # on the reservation to begin with.
I think it will probably depend on the property and who you ask to change the reservation. The OP can certainly ask at each property and see what happens.