If you want to charge back to your room, put down a credit card/ debit card
I buy UO gift cards in advance and put them on my account when I check in
I do check my room balance at times to see where I am at in my charge back spending
Your room charge for the rate you booked with will be a charge in your account the next day
So I put down gift cards for that also sometimes
When I check out, I have any remainder charges go on my cc I have on file
Charges are on your account after midnight so I settle up on my bill the day before I check out
I'm onsite for 16 days so that is another reason I put down a lot of gc on the account
For the times I do not buy a lot of gc in advance, I use traveler checks at check in