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 1065 for tax year (TY) 2023. 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 1065 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 (ATS) and production. Form 1065 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 schema and business rules packages. Instructions for accessing the SOR mailbox Tax year 2023 documents Tax year 2023 1065 MeF accepted forms and schedules PDF Tax year 2023 1065 MeF forms attachment listing XLSX Tax year 2023 1065 MeF return due dates PDF Tax year 2023 stylesheets: MeF stylesheets Tax year 2023 known issues and solutions XLSX – Revised 09/17/2024 Form 1065 links to TY2023 release memos Version Available date ATS date Production date Comments 2023v5.3 10/10/2024 Start: 11/17/2024 End: TBD Start: TBD End: TBD 11/12/2024 - updated business rules package provided 2023v5.2 04/18/2024 Start: 06/02/2024 End: TBD Start: 06/16/2024 End: TBD 08/29/2024 – updated business rules package provided 2023v5.1 02/08/2024 Start: 03/03/2024 End: TBD Start: 03/17/2024 End: TBD 2023v5.0 11/13/2023 Start: 12/17/2023 End: TBD Start: 01/16/2024 End: TBD 12/28/2023 – updated business rules package provided 04/18/2023 – updated business rules package provided 2023v4.0 10/12/2023 Start: 11/19/2023 End: 12/16/2023 Not valid for production 2023v3.0 08/31/2023 Start: 10/23/2023 End: 11/18/2023 Not valid for production 2023v2.0 07/20/2023 Not valid for ATS Not valid for production 2023v1.0 06/08/2023 Not valid for ATS Not valid for production Valid XML schemas and business rules for 1065 Modernized e-File (MeF) Modernized e-File (MeF) schemas and business rules
