Modernized e-File (MeF) status


Modernized e-File (MeF) operational status

Modernized e-File (MeF) production calls

When: Tuesday, January 30, 2024, Wednesday, January 31, 2024, and Thursday, February 1, 2024

Time: 2 p.m. Eastern time

Call-in number: 888-331-8226, participant code 3600320

Call Logs:

Filing season start dates:

Business tax returns: 9 a.m. Eastern time, January 16, 2024

Individual tax returns: 9 a.m. Eastern time, January 29, 2024

Known issues and solutions

Known Issues and Solutions are temporary workaround solutions to allow returns to be e-filed. A separate Known Issue and Solutions is available for each tax year.


The IRS requires an account to access e-Services and other online services (updated 6/2/2023): E-Services transitioned the MeF application to a modernized sign-in system that requires users to register and sign in with to access the e-Services suite of online applications. is an account created, maintained, and secured by a technology provider.

MeF Working Group meetings (updated 2/15/2023): States and external partners are encouraged to attend the MeF Working Group meetings to keep updated on the status and changes to the MeF Program. MeF Working Group meetings are generally held once a month. If you would like to receive a calendar invite for the meetings, please send your name, company name, and email address to the MeF mailbox with a request to be added to the MeF Working Group meeting distribution list.

Transport Layer Security (TLS) version update (updated 7/8/2022): MeF discontinued the use of TLS 1.0 or 1.1 in ATS starting January 2022 and in Production on August 1, 2022. If you are still using TLS 1.0 or 1.1. we ask that you switch to use a higher version of TLS as soon as possible to avoid any possible disruption in service.

Modernized e-File (MeF) System resiliency: Starting with release 10.5 (start date 10/12/2021 for ATS and January 2022 for production) MeF has implemented a new feature which allows the application to function in a limited capacity during system outages. The feature known as “MeF Resiliency” will allow only Send Submissions service and issue response until the system is back to normal operations. All other services such as Get Acknowledgments and state related services will not be available during Resiliency mode (or Portal Mode). Once the system is back online, all services will be restored, and transmitters/states will be able to retrieve acknowledgements and perform their normal operations.

Refer to Resilience frequently asked questionsPDF for additional details.

Critical update for MeF System: The MeF system has tightened cryptographic requirements to conform to government-wide guidance and upgrade from digests using the SHA-1 algorithm in digital and XML signatures. As a result, MeF Production and Assurance Testing System (ATS) environments no longer accept signature and digest methods using SHA-1. An error will be generated if SHA-1 is used, therefore you must switch to SHA-256 or higher. Those with RSA certificates may use SHA-384 or SHA-512.

The most common signature method can be found at XML Signature WG and the most common body part digest can be found at XML Encryption Syntax and Processing.

For more information about detailed method URIs for the newer digests please review information found at XML Security Algorithm Cross-reference.

Note: When clicking on the links above you will leave and be directed to another site.

Schemas and business rules (updated 3/4/2024): Beginning September 2016 software developers and state organizations started receiving the schemas and business rules through their e-Services mailbox rather than downloading them from the IRS website. In order to access these files you must have an active e-Services account and be listed on an e-file application with the provider option of software developer or state. Your role must be responsible official, or delegated user with MeF authorities. These mailbox messages are purged after 60 days so please make sure to download them as soon as possible. Instructions to access the Secure Object Repository (SOR) mailbox were created for your use. You may access the login page, register for e-services, reset your password, and make changes to your existing account on e-Services online tools for tax professionals.

Refer to Modernized e-File (MeF) schemas and business rules for additional details on versions and dates for each form family. (Updated 3/15/2017)

MeF processing year messages

Distribution of Modernized e-File (MeF) new Web Service Definition Language (WSDLs):

(Updated 12/11/2023)

WSDLs for tax year 2023/processing year 2024 (WSDL version R10.7) are available now.

The new WSDLs are scheduled to be installed in the MeF Assurance Testing System (ATS) environment in early fall of 2023. They will be required for MeF production for processing year 2024.

To request a copy of the latest WSDLs please send a request to MeF mailbox at with your company name and ETIN.

As a reminder you should be using the "la.alt" (la.alt.www4) for ATS and "la" main" URL (la.www4) for production environments.