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) 2023. 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 4163 PDF and Publication 4164 PDF. Test scenarios for Form 1041 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 (ATS) and Production. Tax year 2023 documents Tax year 2023 1041 MeF accepted forms and schedules PDF Tax year 2023 1041 MeF forms attachment listing XLSX Tax year 2023 1041 MeF return due dates PDF Tax year 2023 stylesheets: MeF stylesheets Tax year 2023 known issues and solutions XLSX – Revised 7/1/2024 Form 1041 links to TY2023 schemas, business rules, and release memos Version Available date ATS dates Production dates Comments 2023v7.1 10/10/2024 Start: 10/28/2024 End: TBD Start: TBD End: TBD Business Rules Change Page dated 10/10/2024 2023v7.0 04/18/2024 Start: 06/02/2024 End: 10/27/2024 Start TBD End: TBD Valid XML schemas and business rules for 1041 Modernized e-File (MeF) Modernized e-File (MeF) schemas and business rules