This bill mandates the validation of Electronic Filing Identification Numbers (EFINs) before they can be used to electronically file tax returns or other documents. An EFIN, which is a unique identifier issued by the Secretary of the Treasury, must be confirmed as active and authorized for the specific electronic filing activity. Electronic filing software will be required to integrate this validation process, preventing filings from EFINs that have not been properly validated. The Secretary of the Treasury is tasked with establishing a comprehensive, real-time EFIN validation program within 24 months of the bill's enactment. This program will validate EFINs prior to their initial use and at regular intervals, identifying any that are suspended, revoked, or otherwise ineligible. Furthermore, the Secretary must submit an implementation plan to Congress within 180 days and a post-implementation report within two years, detailing the program's design, performance, and any necessary adjustments.