Federal employees on official travel will have to start putting most expenses on government-issued charge cards effective at the beginning of March, the General Services Administration says. The policy, ordered by a law passed in 1998, originally was to have taken effect January 1 but agencies needed more time to prepare for it. Exceptions to the general requirement for using the card include laundry and dry cleaning services, parking, local transportation including taxis, tips, phone calls and expenses incurred where the travel charge card isn’t accepted. Until now, policies on exactly what had to be put on the official charge cards varied from agency to agency.