The following 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 1041 for Tax Year (TY) 2018. Included are the 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 4163 PDF and Publication 4164 PDF. Test Scenarios for 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 2018 Documents Tax Year 2018 1041 MeF Accepted Forms and Schedules PDF (11/28/2018) Tax Year 2018 1041 MeF Forms Attachment Listing XLS (11/28/2018) Tax Year 2018 1041 MeF Return Due Dates PDF Tax Year 2018 Stylesheets: MeF Stylesheets Tax Year 2018 Known Issues and Solutions XLSX – Revised 08/07/2020 Form 1041 links to TY2018 Schemas, Business Rules and Release Memos Version Available Date ATS Dates Production Dates Comments 2018v5.2 02/12/2020 Start: 03/08/2020 End: TBD Start: 03/22/2020 End: TBD 12/08/2020 Business rule updates provided 10/16/2020 Business Rule updates have been provided 09/02/2020 Business rule updates have been provided 2018v.5.1 11/26/2019 Start: 12/29/2019 End: TBD Start: 01/07/2020 End: TBD Business Rule Change Page (11/26/2019) 07/22/2020 Business Rule updates provided 2018v5.0 11/28/2018 Start: 12/30/2018 End: TBD Start: 12/30/2018 End: TBD Business Rule Change Page (02/13/2019) Current Valid XML Schema and Business Rules for 1041 Modernized e-File (MeF) Modernized e-File (MeF) Schemas and Business Rules
