The tables below provide links to the Tax Year 2021 XML Schemas, Business Rules, and Release Memorandum for the Employment Tax Forms (Form 94x series). Throughout the year, multiple versions of Schemas and Business Rules may be in use at the same time. The table reflects the effective dates in the Assurance Testing System (ATS) and Production System, for each version. Tax Year 2021 Documents Tax Year 2021 94x MeF Accepted Forms and Schedules Tax Year 2021 94x MeF ATS Information Tax Year 2021 94x MeF Forms and Attachment List Tax Year 2021 94x MeF Return Due Dates Tax Year 2021 94x MeF Stylesheets Tax Year 2021 Known Issues and Solutions - Revised 08/05/2021 Tax Year 2021 Form 941x (Quarterly Forms) Version Available Date ATS Dates Production Dates 2021 v3.0 05/29/2021 Start: 06/20/2021 End: TBD Start: 07/01/2021 End: TBD 2021v2.1 02/22/2021 Start: 03/07/2021 End: 06/20/2021 Start: 04/01/2021 End: 07/01/2021 2021v2.0 11/21/2020 Start: 12/13/2020 End: 06/20/2021 Start: 04/01/2021 End: 07/01/2021 2021v1.1 10/17/2020 Start: 11/22/2020 End: 12/12/2020 Not Valid for Production 2021v1.0 07/22/2020 Start: 11/02/2020 End: 12/12/2020 Not Valid for Production 94x Online Signature PIN Registration Application Version Available Date ATS Dates Production Dates CUv3.0 05/17/2018 Start: 10/29/2018 End: TBD Start: 01/08/2019 End: TBD Form 9465 Version Available Date ATS Dates Production Dates CUv24.0 10/17/2020 Start: 11/22/2020 End: TBD Start: 02/12/2021 End: TBD CUv23.0 09/02/2020 Start: 11/02/2020 End: 11/21/2020 Not Valid for Production CUv22.0 07/22/2020 Not Valid for ATS Not Valid for Production CUv21.0 07/23/2019 Start: 11/04/2019 End: 11/01/2020 Start: 01/07/2020 End: 02/11/2021 Schemas and Business Rules for Employment Tax Modernized e-File (MeF) FormsModernized e-File (MeF) Program Information
