The following links provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File Forms 1120, 1120-F, and 1120-S. You will find the Extensible Markup Language (XML) Schemas, Business Rules and other useful information separated by tax year. Forms 1120, 1120-F, and 1120-S stylesheets can be downloaded for use in displaying XML tax return data. Production and Assurance Testing System (ATS) - Current valid schemas Tax year Form type 2024 Form 1120, 1120-F, and 1120-S 2023 Form 1120, 1120-F, and 1120-S 2022 Form 1120, 1120-F, and 1120-S 2021 Form 1120, 1120-F, and 1120-S Modernized e-File (MeF) schemas and business rules
