"FlyerTalk community specifically notes the MMM code as "the go-to code for the Minneapolis/St. Paul area, described as extremely reliable at local Courtyard and Residence Inn properties, with a low risk rating." One user documented using an IBM rate for 14 years at 80-100+ nights annually and "never once being asked for an ID." Another stayed 500+ nights and was never asked. The 3M code is regionally well-known near 3M's Minnesota HQ."

"I think the last time I was asked for proof was in a JW Marriott in Beijing. I have never been asked in the US or Europe. Without a business card or ID, you may have an issue. Maybe you can contact the hotels in advance to see what info they need. I don’t remember if LinkedIn is available in China so I would talk to your Corp Travel team to see what they can do. Good news is that hotels are so much cheaper in China compared to ROW right now. ."

"I have been a Platinum for a few years (which implies I frequent Marriott properties on a regular basis) and up until tonight was NEVER asked for any id to justify a corporate rate or discount (I legitimately use a few corporate rates I am entitled to and AAA rates)"