Yes, you may reimburse an employee an advance room deposit, when such a deposit is required by the lodging facility to secure a room reservation, prior to the beginning of an employee's scheduled official travel. However, if the employee is reimbursed the advance room deposit, but fails to perform the scheduled official travel for reasons not acceptable to the agency, resulting in the forfeit of the deposit, the employee is indebted to the Government and must repay that amount in a timely manner as prescribed by you.
41 C.F.R. §301-71.301