[Request for Decision Concerning Reimbursement for Use of Rental Car]

An Immigration and Naturalization Service official requested an advance decision as to whether an employee on temporary duty should be reimbursed using the customary per diem rate plus the cost of the use of a rental car, or whether he should be reimbursed at a lower rate without an allowance for the rental car. The employee, an immigration judge, was assigned temporary duty in Puerto Rico to conduct immigration hearings. The employee stayed at commercial lodgings for the majority of the time during his assignment and used a rental car for transportation. The travel order authorizing the higher rate had been prepared in error; however, an administrative error which sets a per diem rate contrary to a rate established by an agency regulation need not be enforced. Furthermore, teletype messages establishing the special lower rate had been communicated to officials prior to the time of the employee's travel order and, therefore, superseded the rate shown on the travel order. Although an employee may not be required to occupy Government quarters while on assignment, the agency stated that it would best serve the operational needs of the processing center to have all employees lodged in Government quarters. Accordingly, the employee may be allowed only the special per diem rate applicable to the area in which Government quarters were available to him, unless the agency determines that the employee's unusual circumstances warrant his use of the higher rate and the rental car.