"Morgan Stanley's Marriott code MOS is listed alongside Goldman Sachs and UBS codes in FlyerTalk's compilation of financial institution corporate codes. The SF Marriott and midtown Manhattan Marriotts were specifically cited in enforcement threads as properties that "cracked down on corporate code abuse." For financial sector codes, the discount threshold triggers audit flags — if Morgan Stanley's rate is 20%+ below BAR, full-service properties are more likely to verify. US domestic verification: 10-20% at urban full-service; Europe/Asia: meaningfully higher. No MOS-specific denial incident documented."

"I work for the front desk, at a Marriott, & have for the last 8 years .... So when it comes to room upgrades; it goes based on AVAILABILITY... sometimes no matter the tier, if we have it available - I will upgrade the guest. Now of course, higher tiered members get dibs on the upgrades first but after we go through the higher tiered members, Ambassador, Titanium, Platinum - then we go through the other ones. I cannot express this enough : BEING NICE & POLITE AT THE DESK GOES A LONG WA"

"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."