"The AON Hyatt code delivers unusually deep discounts at certain European properties, notably Paris. Hyatt is known as more verification-active than Marriott: "Hyatt is notorious for checking for ID and being quite thorough." Park Hyatt properties explicitly state "Valid Company ID Required at Check-in." One verified traveler reported Park Hyatt Tokyo demanding proof or threatening rack rate conversion, taking 15 minutes of email-searching to satisfy. For AON specifically, no denied-rate incident was found, but Hyatt's general enforcement rate is estimated at 10-20% of stays."

"I guess I just don't see this. I'm not saying rates never changes, but if it really changed every time someone booked a corporate rate, then the rates would change constantly. I can't say that I see this too often or ever. Also I doubt there's enough people doing this to have a huge effect on overall occupancy anyway."

"We are pleased to note you have a future reservation on xxxxxx, 2010 made through hyatt.com. I do kindly ask that you bring your valid working ID in order for us to be able to confirm the corporate rate at time of check-in which will be cross referenced with the company. Unfortunately of late we have been experiencing misuse of some of our corporate rates, with your company a target and we have had to implement tighter controls in this regard."