Yes, except when advance written or electronic authorization is not possible or practical and approval is in accordance with §§301-2.1 and 301-2.5 for:

(a) Use of other than coach-class service accommodation on common carriers or use of other than lowest first-class accommodation on ships;

(b) Use of a foreign air carrier;

(c) Use of reduced fares for group or charter arrangements;

(d) Use of cash to pay for common carrier transportation;

(e) Use of extra-fare train service;

(f) Travel by ship;

(g) Use of a rental car;

(h) Use of a Government aircraft;

(i) Payment of a reduced rate per diem;

(j) Payment of actual expenses (see §301-70.201 for when you may issue a blanket actual expense authorization);

(k) Travel expenses related to emergency travel;

(l) Transportation expenses related to threatened law enforcement/investigative employees and members of their immediate families;

(m) Travel expenses related to travel to a foreign area, except as provided by agency mission;

(n) Acceptance of payment from a non-Federal source for travel expenses (see chapter 304 of this title); and

(o) Travel expenses related to attendance at a conference.

[FTR Amdt. 70, 63 FR 15974, Apr. 1, 1998, as amended by FTR Amdt. 2005-03, 70 FR 28460, May 18, 2005; FTR Amdt. 2007-05, 72 FR 61539, Oct. 31, 2007; FTR Amdt. 2009-06, 74 FR 55150, Oct. 27, 2009; FTR Amdt. 2011-03, 76 FR 55275, Sept. 7, 2011]