That's not proof for the purposes of reimbursement. It only shows that your stay was booked at a particular rate, but not that you paid for it at that rate. The stay could have been comped. Or a third party picked up the costs. Perhaps a credit card statement showing the actual charges to one's account would be required, and that could delay the reimbursement for several weeks.

My employer always requires not just a confirmation of the rate booked, but an actual zero-balance check-out receipt showing the actual amount charged to my credit card. They don't even accept a "zip-out" bill that hotel puts under your door in the morning, because it only says that a certain amount is going to be charged to your credit card.

I know I'd have a big problem trying to get reimbursement if I got a receipt similar to what sosafan and letiole got. From now on I'll steer away from "prepaid" rates, just to be on the safe side, although different properties apparently treat those "prepaid" rates differently. For example, relatively recently I stayed at the Hilton Montreal Airport on a prepaid, non-refundable web rate. At check-in they ran my card and asked me to initial the rate on the slip. When I noted that it was a prepaid rate, they told me that they actually did not charge my card in advance (and it was their policy, not just a weird exception). As a result, I got a regular folio printout at check-out.

The thing I really don't like is inconsistency!