"E&Y (alt) Marriott code 253511 is a secondary Ernst & Young code, alongside the primary EYC code. Fishbowl posts from Big 4 staff: "How do I use the Acc or E&Y codes at Marriott and get around the ID check piece?" — confirming that consulting firm ID checks are a well-known friction point. The same risk profile applies to secondary codes: US select-service essentially never checks; US full-service 10-20%; international meaningfully higher. EY (Ernst & Young) branded itself as EY globally in 2013 — some properties may still see "Ernst & Young" in the code description."

"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 have been asked to show some proof couple of times. I normally show my corp id but credit card with employers name on it has worked, too. As would probably just showing my laptop with employer e-mail account or whatever. My impression has been they are happy with just about anything that proves I'm working for the company whose rate I use and why wouldn't they."