Modernized e-File (MeF) User Guides and Publications

General information and technical guidance for Electronic Return Originators, Software Developers and Transmitters who participate in Modernized e-File (MeF) is provided below.

General Information

SSL Certificates (Updated on 08/09/17): These are effective from 08/09/2017


  • Publication 1220, Specifications for Electronic Filing of Forms 1097, 1098, 1099, 3921, 3922, 5498, and W-2G
  • Publication 1345, Handbook for Authorized IRS e-file Providers of Individual Income Tax Returns
  • Publication 1436, Tax Year 2018 Assurance Testing System (ATS) Guidelines for Modernized e-File (MeF) Individual Tax Returns
  • Publication 3112, IRS e-File Application and Participation
  • Publication 4163, Modernized e-File (MeF) Information for Authorized IRS e-file Providers for Business Returns
  • Publication 4164, Modernized e-File (MeF) Guide for Software Developers and Transmitters
  • Publication 5078, Modernized e-File (MeF) Test Package (Business Submissions)

User Guides

Application-To-Application (A2A) Toolkit

The A2A MeF Software Development Kit (SDK) Toolkit provides software tools and documentation making it easier to build the A2A Client Application for transmitters and states. The toolkit will make it much easier to set up the service requests you need to develop to access the MeF system.

The A2A Toolkit is available to those transmitters and states interested in using the Modernized e-File (MeF) system to send or receive returns. If you are interested in receiving the toolkit, please send an e-mail to the MeF Mailbox to request a copy. Please put A2A Toolkit in the subject line.

If you are using Strong Authentication in your transmissions you must purchase Strong Authentication Certificates.  Information on the Strong Authentication Certificates and where they can be purchased can be found at the following sites:

Approved GSA Digital Certificates
IdenTrust ORC
  • It will take between 7 to 14 days for a digital certificate to be issued after you have notarized your paper work and submitted it to the company.
  • It is imperative that affected contractors keep their digital certificates current. An expired digital certificate will delay the ability to submit.

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