How software can e-file Form 941: what the IRS requires

Last reviewed 2026-11-05. IRS sources read on 2026-10-18. General information only, not tax, legal or accounting advice. IRS rules change; check the linked IRS pages before you rely on anything here.

Short answer

Software transmits a Form 941 to the IRS through the IRS Modernized e-File (MeF) system. Before a company can do that, it has to be accepted into the IRS e-file program. The IRS publications we read describe four things: an e-file provider application that results in an Electronic Filing Identification Number (EFIN) and an Electronic Transmitter Identification Number (ETIN); annual Assurance Testing System (ATS) testing of the software for each form it supports; a one-time communications test for transmitters; and building to the IRS-published XML schemas and business rules. ^{[S1, S2, S7, S8]}

What is Modernized e-File (MeF)?

MeF is the IRS system that receives electronically filed returns. The IRS’s MeF program page is the hub that links to ATS information, schemas and business rules, and user guides. ^[S3] The IRS lists Forms 940, 941, 944 and others under Employment Tax among the forms on its MeF forms page. ^[S4] IRS Publication 4164 is the guide for software developers and transmitters. It sets out the communication procedures, transmission formats, business rules and validation procedures for returns sent through MeF, and says software developers should use it together with the XML schemas the IRS makes available each year. ^[S7]

Publication 4164 describes two ways to send a file to MeF: Application-to-Application (A2A) and the Internet Filing Application (IFA). ^[S7] Software that uses A2A must register each system with the IRS to get Application System IDs (ASIDs); without registration it cannot access MeF. ^[S8]

What does the IRS require before software can e-file a Form 941?

1. Decide which role you play. Publication 5078 describes Software Developers (who build and test software) and Transmitters (who send returns to the IRS). It says that a Software Developer that intends to transmit production submissions must register as both a Software Developer and a Transmitter. ^[S8]
2. Apply to be an IRS e-file provider. The application is under IRS e-services, so you first need an e-services account. The application collects the firm’s identification information and details for each Principal and Responsible Official, and asks you to choose a provider option. Principals and Responsible Officials who are not certified or licensed professionals (the page names attorneys, CPAs and enrolled agents as examples) must be fingerprinted. The IRS may run a suitability check that can include a credit check, a tax compliance check, a criminal background check and a check for prior non-compliance with e-file requirements. The IRS says approval can take up to 45 days from submission. ^[S1]
3. Receive your EFIN and ETIN. If approved, the IRS sends an acceptance letter that includes the EFIN. The IRS says there is currently no fee for an EFIN. ^[S2] Publication 5078 says all Software Developers and Transmitters must obtain an ETIN and an EFIN through the e-file application process before testing, and that the ETIN assigned in the application must be included in each message sent to MeF. ^[S8] Software Developers are issued a Test ETIN that stays in Test mode to allow year-round testing. Transmitters are issued a Production ETIN, but their Forms Transmission Status starts in Test mode and is moved to Production by the IRS after they pass the required communications test. ^[S8]
4. Pass ATS for the forms you support. ATS is the IRS process for testing software and electronic transmissions before accepting Software Developers and Transmitters into MeF. Publication 5078 says each Software Developer must pass testing for each form type and each tax year it supports, and that this is an annual process. ^[S8] For Form 941, Publication 5078 says that for Processing Year 2026 the Tax Year 2026 quarterly ATS scenarios cover Form 941, Schedule B (Form 941), Schedule R (Form 941), Form 8974 and the 94x Online Signature PIN Registration. It says developers must test and pass at least one Form 941 scenario to get “Pass” status for production, and that separate Software IDs are required for the 94x annual forms, the 94x quarterly forms and the 94x Online Signature PIN Registration. ^[S8] The IRS ATS page lists the 94x scenarios and known issues and, at our reading date, said ATS opened on 13 October 2026 for filing season 2027. ^[S5]
5. Complete the communications test (transmitters). Publication 5078 says transmitters must complete a communications test in their first year to transmit production returns, and do not need to repeat it each year. ^[S8]
6. Build to the IRS schemas and business rules. The IRS publishes XML schemas and business rules each year and distributes them through the e-Services mailbox. Publication 4164 notes that software developers are not required to retest when new schemas are posted, but strongly recommends retesting in ATS when you update your software for them. It lists a Form 941 return schema and a separate Form 941-X schema. ^[S7]
7. Transmit, then handle rejections. For a rejected electronic business return, Publication 4164 describes a ten-day Transmission Perfection Period to correct and re-transmit; if the return is then accepted within that period it is deemed received on the date of the first reject. Publication 4164 also says amended Form 941 returns are filed electronically as Form 941-X, as a parent form. ^[S7]

Which Form 941 details does the IRS note for MeF?

• Publication 4164 lists among its Form 94x exclusions that no Form 941 returns will be accepted for tax periods ending before the first quarter of 2023. ^[S7]
• It also says Form 941 will include direct-deposit refund functionality starting in Tax Year 2026, with additional guidance to come. ^[S7]

What does this mean for AI agents?

This section is our reading of the sources above. It is not IRS guidance. The IRS pages and publications we read describe firms, with Principals and Responsible Officials, that apply, receive an EFIN and ETIN, test their software in ATS and transmit to MeF. They do not mention AI agents. In our reading, an AI agent that prepares a return would still depend on an IRS-accepted software developer or transmitter to test and send it. That is the role efile.technology plans to fill if and when the IRS approves us. Until then we are not that provider.

Related guides

• Why AI agents that prepare returns still need an IRS provider: Why preparing a return and transmitting one are different jobs.
• What an IRS-facing MCP tool has to get right: a checklist: Six checks for MCP tools that send filings to a tax authority.
• Docs for the mock MCP server: the mock does not file with the IRS.

What this page does not cover

• Which employers must or may e-file Form 941, and filing deadlines.
• Taxpayer signature and authorization requirements in detail. The 94x Online Signature PIN Registration appears in the ATS scenarios, but we did not review the signature rules.
• IRS Publication 3112 (IRS e-file Application and Participation) and Publication 4163 (MeF information for authorized e-file providers of business returns). They are listed by the IRS and referenced in the sources above, but we did not read them in full. ^{[S6, S8]}
• State requirements, fees other than the EFIN fee statement above, and IRS advertising standards.

Developers can try a mock of these steps (it does not file with the IRS) in the Form 941 mock docs and the Form 944 mock docs.

Sources

All sources are IRS publications or irs.gov pages, read on 2026-10-18. The “reviewed” column is the date shown on the IRS page itself, or the publication revision.

IRS pages change. If a link has moved, search irs.gov for the title.

Where efile.technology stands

We plan to offer Forms 941 and 944 first, with the business extension Form 7004 to follow; more forms later, if and when the IRS approves us. We are preparing for IRS testing and not yet approved to transmit returns. What is efile.technology? · FAQ · Join the waitlist