REVENUE MEMORANDUM CIRCULAR NO. 17-2026 issued on March 9, 2026 notifies all internal revenue officials, employees and others concerned about the loss of five (5) pads of unused/unissued BIR Form No. AF51 -Accountable Form No. 51 bearing Serial Numbers ACF201400273751 – ACF201400274000.

Said forms, which were reported as lost by Administrative Section OIC-Chief Emee B. Zarate of Revenue District Office No. 75, have been cancelled and all official transactions involving the use thereof are considered as invalid.