The last time I did book an agent rate the hotel did not want to let me have it at checkin even though I had business cards, IATAN card and information with me showing I was on company business. They wanted a letter from management on company letterhead as well. Only after I told them that I could get a letter faxed the next morning from our headquarters would they let me check in at the agent rate. They said it was because so many non legitimate "agents" abused the policy. That really makes makes me mad.