"Mitsubishi's Hyatt code (11657) follows Hyatt's standard corporate verification pattern. FlyerTalk users report 50% ID check rate across Hyatt stays in Asia, mitigated by "self-printed business cards that worked 100% of the time." Mitsubishi is a major Japanese conglomerate with strong presence at Hyatt properties in Tokyo, Osaka, and Singapore. Park Hyatt Tokyo has specific documentation of requiring "badge, business card, and email confirmation" for corporate rates. Hyatt Place/House properties globally: essentially never check."

"I don’t really know how they truly enforce this. A lot of companies don’t even put the company name or brand on ID cards anymore due to security concerns (if you find a card on the ground it’s a lot harder to know where to use it). In 20 years of traveling for work I’ve only been asked for a form of ID one time, which was in Germany, and sending the front desk agent an email from my corporate email address took care of their concern."

"I actually used to work for the Park Hyatt Sydney several years ago, in sales and marketing. Every year corporate rates are negotiated based on the number of room nights from the previous year. I can assure you that the abuse of these codes will not go unnoticed. While a chainwide code may apply, it wouldn't be difficult for IBM to see that rates were being used at a property they may not utilise, such as the Park Hyatt Sydney due to the high average room rate, and realise that the code was being abused. They will also notice a significant spike in room nights booked."