"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 have stayed 100s of times with various corporate rates (including Japan) and the only hotel that has asked is W hotels. Even then they didn’t push much. I have been a consultant for 20 years and many clients require you to use their rates when they are paying the bill. The hotel doesn’t have an up to date list of every employee that works for a company globally. The woman at the W said “I don’t really care, just show me anything on your phone that says your name and that company. You can type an email now “."

"My employer does not have a corporate rate but when I'm consulting for a company that does, I use theirs. I've only been challenged for identification once. In that one situation I explained the consulting arrangement, and the desk clerk accepted it without a badge or business card (neither of which I had anyway)."