Valid XML schemas and business rules for 1139 Modernized e-File (MeF)

 

The following links provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Modernized e-File Form 1045 and Form 1139. You will find the Extensible Markup Language (XML) Schemas, Business Rules and other useful information separated by tax year.

Form 1045 and Form 1139 stylesheets can be downloaded for use in displaying XML tax return data.

Production and Assurance Testing System (ATS) - Current valid schemas
Tax yearForm type
2025Form 1045, 1139

Modernized e-File (MeF) schemas and business rules

Page Last Reviewed or Updated: 24-Apr-2026