The following links provide information and technical guidance for Software Developers and Transmitters who are interested in developing software for the Employment Tax Modernized e-File (MeF) Forms. You will find the Extensible Markup Language (XML) Schemas, Business Rules, and other useful information and documents by tax year. Production and Assurance Testing System (ATS) schemas and business rules by tax year Tax year Form types 2025 940, 941, 943, 944, 945, and 94x On-Line Signature PIN Registration Application 2024 940, 941, 943, 944, 945, and 94x On-Line Signature PIN Registration Application 2023 940, 940-PR, 941, 941-PR, 941-SS, 943, 943-PR, 944, 945, and 94x On-Line Signature PIN Registration Application 2022 940, 940-PR, 941, 941-PR, 941-SS, 943, 943-PR, 944, 945, and 94x On-Line Signature PIN Registration Application 2021 940, 940-PR, 941, 941-PR, 941-SS, 943, 943-PR, 944, 945, and 94x On-Line Signature PIN Registration Application Software testing Testing information for the Employment Tax Forms is provided on the Modernized e-File (MeF) Assurance Testing System (ATS) page. Employment tax e-signature methods The Employment Tax e-Signature Methods document communicates the signature methods for various Employment Tax Stakeholders. Employment tax e-file frequently asked questions The Modernized e-File for Employment Taxes FAQs communicate common questions and answers regarding the Employment Tax e-File Program. Stylesheets Employment Tax MeF form Stylesheets can be downloaded for use in displaying XML tax return data. Modernized e-File (MeF) schemas and business rules Modernized e-File (MeF) program information