I've been trying to understand how IRS e-file works. Does anyone know if it's a public API, and if so, where I can get information on it? Google has not been helpful.
Best Answer
My company, http://www.aplossoftware.com is an Authorized IRS e-File Provider. It is quite the process to get approved to become an e-file provider for the IRS. Several layers of application, fingerprinting, FBI background checks, to extremely buggy sdk... with few log explanations.
If you are serious about getting into the IRS e-file program, Publication 3112 was a helpful overview of process: https://www.irs.gov/pub/irs-pdf/p3112.pdf
IRS recently updated their site and changed all the urls with no forwarding...
Here is the Modernized e-File main page:https://www.irs.gov/e-file-providers/modernized-e-file-program-information
Another helpful document is Publication 4164, Modernized e-File Guide for Software Developers and Transmitters.
E-file application questions are handled by the e-Help Desk.Here is the e-Help desk email inbox:irs.e-helpm[email protected]You can email that inbox for any specific inquiries.
IRS also does have an SDK. You just have to email the help desk to request it and they'll send you a form to fill out to officially request it.
Good luck..
It looks like this page has the list of documentation for the efile process:https://www.irs.gov/e-file-providers/become-an-authorized-e-file-provider
Was curious about this and things seem to have changed in the last few years with the IRS Modernized e-File program. The basic answer is the API specification is public, but to actually transmit a tax return you have to go through lots of certifications to prove your identity, readiness, and compliance.
The actual technical mechanism is transmission of XML documents described here, bundled with supplementary XML documents and PDF attachments. These are placed in a ZIP file submitted using a SOAP message. Submissions seem to be signed with an IRS-specific set of SSL certificates.
The documentation also mentions a limited-access API, presumably to abstract away some of this activity.