41 CFR § 102-118.115
Must my agency use a GBL?
June 9, 2020
No, your agency is not required to use a GBL and must use commercial payment practices to the maximum extent possible. Effective March 31, 2002, your agency must phase out the use of the Optional Forms 1103 and 1203 for domestic shipments. After this date, your agency may use the GBL solely for international shipments.
[65 FR 24569, Apr. 26, 2000, as amended at 66 FR 48812, Sept. 24, 2001]