"UBS is explicitly discussed on FlyerTalk in the "Corporate ID required???" thread. One user: "Of the numerous Marriotts I've used my corporate code at in the US and Asia, I was only asked once — at the SF Marriott, because that particular hotel has seen a number of people abusing the corporate discount policy." Another: "Asia is the one place where I have been asked to show ID." A commenter noted: "if Marriott was really concerned about abuse, maybe they should have picked something other than stock ticker symbols as the prevalent corp code" — directly referencing UBS-style codes. hotelcorporatecodes.com: "⚠️ Sometimes," 10-15% discount. Financial services codes at full-service urban Marriotts in Europe (London, Zurich) carry meaningfully higher risk."

"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 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."