Generally, no, an agency must not revise or alter amounts on a GSA Form 7931. The only change an agency can make to a GSA Form 7931 is to change the agency financial data to a correct cite. Any GSA Form 7931 that cannot be paid (e.g., an amount previously paid), must be immediately returned to the GSA Transportation Audits Division with an explanation.
41 C.F.R. §102-118.510