Some agencies require you to use a govt. cc for plane tickets which get purchased for you by a travel agency, but it's a function of who pays the credit card company for charges on the govt. card.

Obviously if all charges get paid by the govt, the card has to be used for everything that gets reimbursed, but if the govt. sends the employee a reimbursement check, it's up to him/her to pay the cc companies.

ad nauseum

Bob H