301-51.5—How may I pay for official travel expenses if I receive an exemption from use of the Government contractor-issued travel charge card?

If you receive an exemption from use of the Government contractor-issued travel charge card, your agency may authorize one or a combination of the following methods of payment:
(a) Personal funds, including cash or personal charge card;
(b) Travel advances; or
(c) Government Transportation Request (GTR).

Code of Federal Regulations

Note to § 301-51.5 : City pair contractors are not required to accept payment by the methods in paragraph (a) or (b) of this section.