The links below provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File (MeF) Form 7004 for tax year 2021. Developers and other authorized IRS e-file providers can find information on e-filing returns through MeF in Publication 4163 PDF and Publication 4164 PDF. The Form 7004 test scenarios can be found on the Modernized e-File (MeF) Assurance Testing System (ATS) page. Extensible Markup Language (XML) Schemas, Business Rules, and Release Memorandum - Throughout the year, multiple versions of these documents may be in use at the same time. Special attention should be paid to the Release Memo issue date and the projected start and end dates for Assurance Testing System and Production. Form 7004 Schemas and Business Rules are now distributed through the registered user portal and your e-services mailbox. This mailbox is part of the Secure Object Repository (SOR). Users will access their mailbox in their existing e-services account to pick up the Schemas and Business Rules packages. Instructions for accessing the SOR mailbox Tax year 2021 documents Tax year 2021 Form 7004 MeF return due dates PDF Tax year 2021 stylesheets: MeF stylesheets Tax year 2021 known issues and solutions XLSX – Revised 03/26/2024 Form 7004 links to TY2021 release memos Version Available dates ATS date Production dates Comments 2021v1.0 06/12/2021 Start: 10/12/2021 End: TBD Start: 01/07/2022 End: TBD 06/09/2022 Business rules updates provided XML Schemas and Business Rules for Form 7004 Modernized e-File (MeF) Modernized e-File (MeF) Schemas and Business Rules
