You got lucky. DH has a CAC (government issued contractor id card) and a letter on Army letterhead every time he travels which explicity states where and when he is travelling and the authorized per deim rate for that city. He still can't get the per diem at most US Marriott family hotels. (Those in Germany have been more likely to give it too him) He is fortunate that if he can show his company that no per diem rates were avaiable within a reasonable distance of the Army post he is visiting they will reimburse him the difference and eat the cost. I guess they are charging the Army enough to make it worth their while.