"Sixt's Hilton code D343260360 is for the German car rental company. Car rental corporate codes at hotels present an unusual dynamic — Sixt is a corporate account as a travel partner, not an employer benefit for its own staff. No FlyerTalk thread discusses Sixt Hilton employee verification. Car rental company codes are low-enforcement at all hotel brands: hotels see Sixt as a booking channel partner, not a confidential employee benefit program."

"I have a client that requires me to use their rate when traveling on their dime. I’ve never been asked to provide ID, but I can simply say that I’m a contractor for said company."

"FlyerTalk's dedicated Hilton FedEx thread provides community data: "Hilton is hit or miss about checking for special codes. I have used several codes, all real, and have been asked maybe 20% of the time to show proof." Another user: "I honestly can't remember the last time I made a reservation without some kind of corp code. I have never once been asked to show any sort of ID." FedEx reportedly monitors Hilton usage volume, which could affect contract renewal terms. HotelCorporateCodes.com rates this as "Sometimes.""