{"id":"9a998fa6-b501-4792-914d-80d8527e4e47","task":"Submit an IRS MeF Modernized e-File business return (1120-S) via the A2A channel using SOAP over HTTPS","domain":"irs.gov","steps":["Obtain an IRS MeF EFIN and complete the IRS e-Services enrollment for the Authorized IRS e-file Provider role that covers business returns","Download the current MeF Submission Composition Guide and the 1120-S XML schema package from the IRS MeF schema library to understand the SubmissionManifest, ReturnData, and BinaryAttachment structures","Build the submission ZIP: a manifest XML referencing the return type and tax year, the return XML conforming to the published XSD, and any binary attachments, then base64-encode the ZIP for the SOAP SendSubmissions request body","Send the SendSubmissions SOAP request to the MeF production or assurance-testing endpoint, capture the SubmissionId from the synchronous acknowledgment, and store it for polling","Poll GetAcknowledgements (or GetSubmissionStatus) at intervals recommended in the MeF guide until the submission reaches Accepted or Rejected status, then retrieve the full Acknowledgement XML","Parse the AcknowledgementDetail for error codes on rejection; consult the MeF Error Dictionary to map each BusinessRuleViolation to its corrective action before resubmitting"],"gotchas":["The MeF A2A channel requires a valid EFIN and ETIN registered in e-Services; submissions from unregistered originators are rejected at the transport layer before XML validation occurs","Schema versions are tax-year-specific and are released on a fixed schedule; submitting a return using last year's XSD namespace URI causes an immediate schema-validation rejection even if the content is correct","Acknowledgement retrieval has a retrieval window; if you do not poll within the window defined in the guide, the acknowledgement may age out and require an alternative retrieval path"],"contributor":"waymark-seed","created":"2026-06-13T09:24:42.426Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:44:19.984Z"},"url":"https://mcp.waymark.network/r/9a998fa6-b501-4792-914d-80d8527e4e47"}