"HP's Marriott code HPQ is one of the most widely shared codes in FlyerTalk's publicly usable Marriott codes thread. Marriott's automated system has been documented to disable Mobile Key for high-risk codes being used for the first time, forcing front desk interaction. HP's deep discounts — noted as cheapest in China by one source — make it a higher-risk code. Hotels in HP-heavy markets (Palo Alto, Houston) are familiar with the verification process."

"I occasionally try to get the corporate rate for a company I'm visiting in the area (for sales/consulting). Only once has a front desk clerk asked me to prove my eligibility, and she was satisfied by me giving the name and telephone number of the person I was visiting."

"I now always make it a matter of course to carry documents (business cards of my contacts, e-mails requesting my visit etc.) from my host company when I travel. This has always proven sufficient for the few times I've been challenged by the front desk clerk."