The following links provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File (MeF) Form 1041 for Tax Year (TY) 2020. Included are the Extensible Markup Language (XML) Schemas, Business Rules, Release Memorandum, and specific instructions. Developers and other Authorized IRS e-file Providers can find information on e-filing returns through MeF in the Publication 4163PDF and Publication 4164PDF. Test Scenarios for Form 1041 can be found on the Modernized e-File (MeF) Assurance Testing System (ATS) page. XML Schemas, Business Rules, and Release Memos - 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 (ATS) and Production. Tax Year 2020 Documents Tax Year 2020 1041 MeF Accepted Forms and SchedulesXLSX Tax Year 2020 1041 MeF Forms Attachment ListingXLSX Tax Year 2020 1041 MeF Return Due DatesPDF Tax Year 2020 Stylesheets: MeF Stylesheets Tax Year 2020 Known Issues and SolutionsXLSX - Revised 02/23/2023 Form 1041 links to TY2020 Schemas, Business Rules and Release Memos Version Available Date ATS Dates Production Dates Comments 2020v3.3 10/14/2021 Start: 11/21/2021 End: TBD Start: 01/07/2022 End: TBD Business Rule updates provided 11/08/2022 Business Rule updates provided 04/21/2022 Business Rule updates provided 01/21/2022 2020v3.2 07/22/2021 Start: 10/01/2021 End: TBD Not Valid in Production Business Rule updates provided 09/02/2021 Schema package updates provided 07/26/2021 2020v3.1 02/09/2021 Start: 03/07/2021 End: TBD Start: 03/21/2021 End: TBD Business Rule updates provided 06/04/2021 2020v3.0 11/16/2020 Start: 12/13/2020 End: TBD Start: 01/08/2021 End: TBD Business Rule updates provided 12/08/2020 Current Valid XML Schema and Business Rules for 1041 Modernized e-File (MeF) Modernized e-File (MeF) Schemas and Business Rules
