I am not sure. I agee with the comment that I don't plan on staying there at all, at least at the Primm Hotel every again.
Last time I made a reservation for a Primm hotel it was 48 hours prior to arrival to avoid one night stay hitting your credit card. They will go over the cancellation policy on the phone with you when you book.
Last I read it was 24 hours or less before the booked date there is a fee for cancelling. It might be up to one day's room rental.
Going through the booking process to that point will answer this question best. Immediate cancellation during the booking process is free.
I don't know; our current personal policy is to cancel the idea of staying there at all.
Get an answer from Primm Valley Resort & Casino staff and past guests.