"General Motors' Hyatt code NC12964 is for one of the world's largest automakers. GM HQ is in Detroit MI — Hyatt Regency Detroit handles GM employees regularly. FlyerTalk's Hyatt verification pattern: 50% ID check rate across international stays, primarily at Park Hyatt and Grand Hyatt properties. Michigan/Detroit Hyatt properties are familiar with GM employee badges and may request them. US domestic Hyatt Place/House: minimal enforcement. No NC12964-specific denial documented."

"Just wanted to let you know that I tried using this code at Hyatt Regency Istanbul, and the guy asked me for ID. I explained that I was a contractor, but he wouldn't buy it and requested further verification. I told him to just charge me the regular rate, and I would get reimbursed. It was only a 25 euro difference per day."

"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."