The rule is the member must book, stay, and pay for the room. Technically, I believe the member only needs to make the last payment. So if you let your guest pay down the folio to $1 so they have a charge on their card for expensing and then you pay off the $1 (just be sure it's in that order), it should past muster. However, you might run into a FDC or back office staff that will take exception. Dynamic rules do pop up from time to time. There were reports of FDCs saying you won't get credit if your company's name was on your CC even if you pay the bill. Fortunately they were wrong.