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) Forms 1120, 1120-F, and 1120-S for Tax Year 2020. Developers and other Authorized IRS e-file Providers can find information on e-filing returns through MeF in Publication 4163PDF and Publication 4164PDF. Directions for Corporations required to e-file can be found through the e-file for Large and Mid-Size Corporations website. Test Scenarios for the 1120 Form Family can be found on the Modernized e-File (MeF) Assurance Testing System (ATS) page. Extensible Markup Language (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 and Production. Form 1120 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 2020 Documents Tax Year 2020 1120 MeF Accepted Forms and SchedulesXLSX Tax Year 2020 1120 MeF Forms Attachment ListingXLSX Tax Year 2020 1120 MeF Return Due DatesPDF Tax Year 2020 Stylesheets: MeF Stylesheets Tax Year 2020 Known Issues and SolutionsXLSX - Revised 02/23/2023 Form 1120, 1120-F, 1120-S links to TY2020 Release Memos Version Available Dates ATS Dates Production Dates Comments 2020v5.3 10/14/2021 Start: 11/21/2021 End: TDB Start: 01/07/2022 End: TBD Business rule updates provided 11/29/2022 Business rule updates provided 11/14/2022 Business rule updates provided ATS and production dates TBD for processing year 2023 07/21/2022 Business rule updates provided 06/09/2022 Business rule updates provided 04/21/2022 Schema and Business rule updates provided 10/12/2021 2020v5.2 06/14/2021 Start: 10/1/2021 End: TBD Start: 01/07/2022 End: TBD Business Rule updates provided 09/02/2021 2020v5.1 02/09/2021 Start: 03/07/2021 End: TBD Start: 03/21/2021 End: TBD Business Rule updates provided 04/22/2021 2020v5.0 11/21/2020 Start: 12/13/2020 End: TBD Start: 01/08/2021 End: TBD Current Valid XML Schemas and Business Rules for 1120/1120-F/1120-S Modernized e-File (MeF) Schemas and Business Rules
