2018 Valid XML Schemas and Business Rules for 1120, 1120S and 1120-F 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 Forms 1120, 1120S and 1120-F for Tax Year 2018.

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 family can be found on the Modernized e-File (MeF) Assurance Testing System (ATS) Page

XML Schemas, Business Rules and 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 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 schema and business rules packages.

Instructions for accessing the SOR mailbox  PDF.

Tax Year 2018 Documents

Form 1120, 1120S, 1120-F links to TY2018 Release Memos

Version Available Dates ATS Dates Production Dates Comments


Start: 03/08/2020 Start: 03/22/2020

Business rule updates provided 
Available in ATS 

07/22/2020 Business Rule updates provided

Available in ATS 

2018v5.3 10/15/2019 Start: 12/8/2019 Start: 01/07/2020 Complete package available including Business Rules.
2018v5.2 02/13/2019 Start: 03/10/2019 Start: 03/17/2019 Schema package update only, no changes to the Business Rules.
2018v5.1 11/28/2018 Start: 12/30/2018 Start: 01/08/2019  
2018v5.0 09/18/2018 Start: 12/09/2018
Start: 01/08/2019 10/17/2018 Complete  package made available  including Business Rules.

Current Valid XML Schemas and Business Rules for 1120/1120S/1120-F

Modernized e-File (MeF) Schemas and Business Rules