What document Mandates the use of a Government sponsored travel card for costs associated with official Government travel.?

The document that mandates the use of a government-sponsored travel card for costs associated with official government travel is the "Federal Travel Regulation" (FTR). Specifically, it outlines the requirements for federal employees to use the Government Travel Charge Card for travel-related expenses, ensuring compliance with federal travel policies. This regulation aims to streamline travel processes and enhance accountability in the use of government funds.