2021 Valid XML Schemas and Business Rules for 1120, 1120-F, and 1120-S Modernized e-File (MeF)


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 4163PDF and Publication 4164PDF. 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) Updates 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

Form 1120, 1120-F, 1120-S links to TY2021 Release Memos

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
Valid for ATS and Production
2021v4.3 04/21/2022 Start: 06/05/2022
End: TBD
Start: 07/24/2022
End: TBD

Business rule updates provided

Business rules updates provided

Business rules updates provided.

Business rules updates provided
ATS and production dates TBD for processing year 2023

Version 2021v4.3 not available in ATS between 07/17/2022 through 07/24/2022

Business rules updates provided

The entire package will be available for production 07/24/2022. 

The Form 1120-S Schedules K-2 and K-3 will be available in production 07/24/2022.  

An early look of Tax Year 2021/ Processing Year 2022 Form 1120-S Schedules K-2 and K-3 schema only. Related business rules will be made available later.

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

Modernized e-File (MeF) Schemas and Business Rules