41 CFR 301-50.3 - Must I use the ETS or TMS to arrange my travel?
Yes, if you are an employee of an agency as defined in § 301-1.1 of this chapter, you must use the E-Gov Travel Service when your agency makes it available to you. Until then, you must use your agency's existing Travel Management Service (TMS) to make your travel arrangements. If you are an employee of the Department of Defense (DoD) or of the Government of the District of Columbia, you must arrange your travel in accordance with your agency's TMS. Your agency may grant an exception to required use of TMS/ETS under § 301-50.4, § 301-73.102, or § 301-73.104 of this chapter.