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 Tax Year 2018 1120 MeF Accepted Forms and Schedules PDF Tax Year 2018 1120 MeF Forms Attachment Listing XLSX Tax Year 2018 1120 MeF Return Due Dates PDF Tax Year 2018 Stylesheets: MeF Stylesheets Tax Year 2018 Known Issues and Solutions XLSX – Revised 08/07/2020 Form 1120, 1120S, 1120-F links to TY2018 Release Memos Version Available Dates ATS Dates Production Dates Comments 2018v5.4 02/14/2020 Start: 03/08/2020 Start: 03/22/2020 Business rule updates provided 11-21-2020 Available in ATS 12-13-2020 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
