Employee Who Failed To Itemize Actual Subsistence Expenses May Not Be Paid Per Diem

An advance decision was requested as to whether an employee may be reimbursed for subsistence expenses during the time that he was performing temporary duty in a high-rate geographical area. Since the travel authorization was for actual expenses and the employee failed to itemize expenses, he may not be paid on a flat-rate basis. Travel orders may not be retroactively amended to provide for per diem reimbursement since there was no showing of error or omission.