41 CFR § 301-51.1
How must I use the Government contractor-issued travel charge card?
June 9, 2020
You are required to activate the Government contractor-issued travel charge card once you receive it, and then use it as the method of payment for all official travel expenses unless exempted under §301-51.2.
[FTR Amdt. 2016-01, 81 FR 63138, Sept. 14, 2016]