"The AMX code for American Express employees is widely circulated. Community members note that "neither Amex Platinum nor Amex Bonvoy cardholders have any special corporate codes — this is strictly for Amex employees." Hotel staff may require employee verification. No specific denial cases documented, but risk noted as moderate given Amex's large employee headcount makes staff less suspicious of claimants."

"I don't do mobile check-in if I'm wanting to upgrade. I check the app before I go in to see if any suites are available to book during the duration of my stay. If there is I just say "Would it be possible to get upgraded to an available suite with my platinum benefit?". Of course this is typically at the hotel that I stay in about once a month for 3 day at a time for work. The front desk pretty much knows me and know that I am fairly low maintenance."

"I have a close friend who is a GM at a Marriott property in a fairly large US city (top 25 metro population). Their opinion is basically, "Hey, it's business. I'm not turning away a paying guest if they don't have the right ID." In this person's younger days as a front desk agent, they enjoyed catching people trying to use a corporate rate that the guest was not entitled to. As they became higher up and saw the books, occupancy rates, etc... Corp ID's became far less important than filling rooms."