"Siemens codes (SIE / 7346) are among the most reliably active corporate codes, showing 15–22% discounts at many global Marriott properties. The code appears in widely distributed PDF documents traceable to 2014. If you are caught, the property can raise your rate to the current rack rate and you could be considered to be defrauding the property. Wide documentation suggests this code has been in circulation for over 10 years."

"I have a close friend who is a GM at a Marriott property in a fairly large US city (top 25 metro population). Their opinion is basically, "Hey, it's business. I'm not turning away a paying guest if they don't have the right ID." In this person's younger days as a front desk agent, they enjoyed catching people trying to use a corporate rate that the guest was not entitled to. As they became higher up and saw the books, occupancy rates, etc... Corp ID's became far less important than filling rooms."

"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."