"United Airlines' Marriott code UAL is an airline employee code. United employee IDs are company-issued physical badges. Properties near United hubs (Chicago O'Hare, Newark, Houston Bush, Denver, San Francisco) regularly handle United crew and employees. FlyerTalk's airline code thread: "Airline codes are more likely to be checked than random corporate codes because the front desk knows what an airline badge looks like." No UAL-specific denial documented. Airport corridor Marriott properties: moderate enforcement."

"I am very rarely asked to prove my eligibility for a rate...but they have every right to ask and if you can't produce it, you will be re-rated to the current rate, which is often even higher and there is no guarantee points rooms will be available. Doing online check in rarely helps this as most properties don't actually do online anyway - especially to people who are not returning guests to the property or elite. You are taking a gamble. One that is likely to be fine. But understand you are intentionally breaking the terms of the bonvoy program and if someone really cared, there can be consequences."

"I swear the front desk employees are trained to resist and encouraged to lie. They try to save the rooms for members with higher status or complainers. I've booked King rooms and they'll assign me a double or a queen. The first rep will tell me they're fully booked and there's nothing they can do. But once transferred to a manager, King rooms magically appear!"