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 720 for Tax Year (TY) 2021. 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 720 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 2021 Documents Tax Year 2021 720 MeF Accepted Forms and Schedules PDF Tax Year 2021 720 MeF Return Due Dates PDF Tax Year 2021 Stylesheets Tax Year 2021 Known Issues and SolutionsXLSX - Revised 03/02/2023 Release Memo Schema Version ATS Date Production Date Business Rules Comments 04/26/2021 Q4v3.2 Q3v3.2 Q2v3.2 Start: 06/06/2021 End: TBD Start: 06/20/2021 End: TBD Q4v3.2 Q3v3.2 Q2v3.2 Business Rules Change Page dated 09/02/2021 02/09/2021 Q4v3.1 Q3v3.1 Q2v3.1 Q1v3.1 Start: 03/07/2021 End: TBD Start: 03/21/2021 End: TBD Q4v3.1 Q3v3.1 Q2v3.1 Q1v3.1 Business Rules Change Page – Q1v3.1, only dated 09/02/2021 10/16/2020 Q4v3.0 Q3v3.0 Q2v3.0 Q1v3.0 Start: 11/22/2020 End: TBD Start: 01/08/2021 End: TBD Q4v3.0 Q3v3.0 Q2v3.0 Q1v3.0 Form 9465 Version Date Available ATS Date Production Date CUv25.0 07/21/2022 Start: 10/24/2022 End: TBD Start: 01/23/2023 End: TBD Modernized e-File (MeF) XML Schema and Business Rules for Excise Tax Form 720