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;
(h)
Use of a Government aircraft;
(i)
Payment of a reduced rate per diem;
(j)
Payment of actual expenses;
(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.
Code of Federal Regulations
Note to § 301-71.105
:
You should establish procedures for travel situations where it is not practical or possible to issue a written authorization in advance, except for paragraphs (c), (i), (n), and (o), which always require written or electronic advance authorization.
Code of Federal Regulations
[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]