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) Forms 1120, 1120-F, and 1120-S for Tax Year 2021.
Developers and other Authorized IRS e-file Providers can find information on e-filing returns through MeF in Publication 4163 PDF and Publication 4164 PDF. Directions for Corporations required to e-file can be found through the e-file for Large and Mid-Size Corporations website. Test Scenarios for the 1120 Form Family 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 and Production.
Form 1120 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 Schemas and Business Rules packages.
Tax year 2021 documents
- Tax Year 2021 1120 MeF Accepted Forms and Schedules PDF
- Tax Year 2021 1120 MeF Forms Attachment Listing XLSX
- Tax Year 2021 1120 MeF Return Due Dates PDF
- Tax Year 2021 Stylesheets: MeF Stylesheets
- Tax Year 2021 Known Issues and Solutions XLSX – Revised 03/26/2024
| Version | Available Dates | ATS Dates | Production Dates | Comments |
|---|---|---|---|---|
| 2021v4.4 | 02/09/2023 | Start: 03/05/2023 End: TBD |
Start: 03/19/2023 End: TBD |
12/28/2023 11/13/2023 Valid for ATS and Production |
| 2021v4.3 | 04/21/2022 | Start: 06/05/2022 End: TBD |
Start: 07/24/2022 End: TBD |
07/20/2023 11/29/2022 11/14/2022 09/01/2022 07/21/2022 07/20/2022 06/09/2022 05/03/2022 04/21/2022 03/17/2022 |
| 2021v4.2 | 02/10/2022 | Start: 03/06/2022 End: TBD |
Start: 03/20/2022 End: TBD |
|
| 2021v4.1 | 11/12/2021 | Start: 12/12/2021 End: TBD |
Start: 01/07/2022 End: TBD |
|
| 2021v4.0 | 10/14/2021 | Start: 11/21/2021 End: TBD |
Start: 01/07/2022 End: TBD |
Current valid XML schemas and business rules for 1120/1120-F/1120-S