"University of Pennsylvania's Marriott code 4309 is an academic institutional code. No FlyerTalk thread discusses UPenn verification incidents. University institutional codes at Philadelphia-area Marriott properties are familiar and unchallenged. Academic travel patterns (conferences, academic visits, faculty stays) are the lowest-scrutiny category at Marriott full-service and select-service properties."

"HotelCorporateCodes.com rates the Marriott DIS code as "Sometimes" for ID verification. No dedicated forum thread found specifically discussing Disney corporate code verification incidents. Disney has 140,000+ US employees and the code is widely circulated. One FlyerTalk user noted that a retired employee who disclosed their retired status was never asked for ID, suggesting properties prioritize rate code volume over strict verification. FL Marriott properties near Orlando HQ are most familiar with the code."

"It’s about 80/20 for me. 80% of the time I still have to go to the front desk. I’ve asked the front desk folks, and they always say “our property has a policy to not allow mobile check-in”… I guess Marriott allows this at the property’s discretion. One property said they don’t want the guest to get stuck with full charges if they end up having travel issues and mobile checked-in the day before."