"GM's Marriott code GMC is confirmed in FlyerTalk's publicly usable codes list alongside Ford (FRD) and Toyota (TOY). No specific verification-denial threads were found. General Motors has major hubs in Detroit/Metro Michigan, and Marriott properties near the Renaissance Center likely handle many genuine GM employees. US verification is rare — geography matters most, with hotels within 5 miles of GM's corporate HQ being the exception."

"I'm guessing so, but I'm not a Marriott employee. Also, to answer some of the other questions floating around here, I have never been asked to produce my work ID when checking into the hotel that I booked using a corporate rate. I travel half a dozen times a year."

"I work for a company that is partially owned by a Fortune 100 company and we have their corporate rate code linked to our travel website, (although it is one of the ones that is very easy to figure out). In 4+ years I've never been asked for any ID, although a few times a year I get the question of "what company are you with?""