The Complete Guide to the IRS FIRE to IRIS Transition (2026)

Key Takeaways

• FIRE retires December 31, 2026. Tax Year 2026 returns (due early 2027) must be filed through IRIS. The IRS is still finalizing how corrections for returns originally filed in FIRE will be handled after retirement.
• Everyone needs an IRIS TCC. Whether you use the IRIS Taxpayer Portal or the A2A channel, you must apply for a new IRIS-specific Transmitter Control Code. Your FIRE TCC does not carry over.
• IRIS validates TIN and Name in real time. Unlike FIRE, where you might wait months for a CP2100 notice, IRIS flags mismatches at submission. Clean data matters more than ever.
• 1042-S is already live on IRIS. As of January 2026, IRIS accepts both 1099 and 1042-S filings.

The End of FIRE

The IRS has officially announced the end of FIRE. After nearly four decades as the backbone of electronic information return filing, the Filing Information Returns Electronically (FIRE) system will be retired on December 31, 2026. Every organization that files 1099s, 1042-S forms, or other information returns electronically will need to transition to the IRS's replacement: the Information Returns Intake System, or IRIS.

If you file information returns for your business or your clients, this isn't a distant concern. Tax Year 2025 is the last year you can file through FIRE. Tax Year 2026 returns, due in early 2027, must go through IRIS. That means your processes, your software, and your team need to be ready well before then.

This guide covers everything you need to know: what's changing, what the timeline looks like, and exactly how to prepare.

What Is FIRE, and Why Is It Going Away?

FIRE has been the IRS's electronic filing system for information returns since the late 1980s. It accepts data in a fixed-width ASCII format defined by IRS Publication 1220. If you've ever filed 1099s electronically, your data was almost certainly transmitted through FIRE, either directly or through a third-party vendor.

The system has served its purpose, but it's aging infrastructure. FIRE lacks real-time validation, offers limited error feedback, and uses a flat-file format that's increasingly out of step with modern data standards. The IRS decided to modernize.

What Is IRIS?

IRIS is the IRS's modern replacement for FIRE. Built on current technology, it accepts data in structured XML format and provides several improvements over FIRE:

• Real-time TIN and Name validation. IRIS checks your Taxpayer Identification Numbers and payee names against IRS records during submission. You get immediate feedback instead of waiting months for a CP2100 or CP2100A notice. Submissions with mismatches receive an "Accepted with Errors" status so you can correct issues right away.
• Two filing methods. A web-based portal (the IRIS Taxpayer Portal) for organizations filing smaller volumes (up to 250 records per CSV upload, with unlimited uploads), and an Application-to-Application (A2A) channel for high-volume filers who want direct system integration.
• Better record management. IRIS stores filed forms and lets you download recipient copies, request extensions, and file corrections, all within the system.
• Structured data. XML format means cleaner data handling, with separate fields for first name, middle name, last name, and business name (FIRE lumped names into a single combined field).
• Broader form support. IRIS now accepts both 1099 series and 1042-S forms, with additional form types planned.

The Timeline: Key Dates You Need to Know

The IRS is encouraging early adoption. If you can start filing through IRIS for Tax Year 2025, you'll have a full filing season to work through any issues before FIRE goes dark.

What's Changing: FIRE vs. IRIS at a Glance

You Need a New IRIS TCC

Your existing FIRE Transmitter Control Code (TCC) does not work with IRIS. You must apply for a new IRIS-specific TCC through the IRS e-Services portal, regardless of how you plan to file.

Both the IRIS Taxpayer Portal and the A2A channel require a TCC. The difference is that portal users do not need an API Client ID or ATS testing. A2A users need both.

If you use a third-party transmitter like Morado, Sovos, or Avalara, your transmitter holds the TCC and files on your behalf. You don't need to apply for your own.

The TCC application process:

1. Register or log into e-Services at IRS.gov.
2. Apply for an IRIS TCC. You'll select your role: Transmitter, Issuer, or Software Developer. You'll also select which form families you need (1099 series, 1042-S). Note: IRIS assigns separate TCCs per form family, similar to FIRE.
3. Complete identity verification. The IRS requires Responsible Official and Contact information with identity proofing.
4. Receive your TCC. For A2A filers, it will initially be issued in "Test" status. You must pass Assurance Testing (ATS) before it's activated for production filing.

Don't wait on this. The application process takes time, and you'll need your TCC before you can test or file.

Understanding the IRIS XML Schema

If your organization files via A2A (the API method), the shift from Publication 1220's flat-file format to IRIS XML schemas is the biggest technical change you'll face.

Key things to know about the XML schema:

• Schema packages are distributed through the IRS Secure Object Repository (SOR). You must have an IRIS TCC to access them.
• Transmissions are identified by a Unique Transmission Identifier (UTID) that you generate.
• Data structure is hierarchical. Each transmission contains submissions, and each submission contains records. This is fundamentally different from FIRE's linear flat-file approach.
• Name handling is stricter. IRIS requires separate XML elements for first name, middle name/initial, last name, and suffix. If your current data combines names into a single field, you'll need to parse them before submission.
• Validation rules are enforced at submission. IRIS checks TIN formatting, amount fields, and required elements in real time.

For organizations currently using Publication 1220 format, this means updating your data export pipelines, reformatting name fields, and generating valid XML that conforms to the IRS schema.

IRIS ATS Testing: What to Expect

Before you can file production returns through IRIS A2A, you must pass the Assurance Testing System (ATS). Portal-only filers do not need to complete ATS. Here's how it works:

• ATS opens annually in the fall (typically October/November).
• Software developers must submit test files with five submissions, each containing two records (10 records total). All must receive an "Accepted" status.
• Transmitters and Issuers must complete a one-time communication test.
• Use test TINs only. All TINs in ATS must begin with three zeros (e.g., 000-11-1111). Never submit real taxpayer data in the test environment.
• Once you pass ATS, your TCC status moves from "Test" to "Production," and you can begin filing live returns.

Common ATS Pitfalls

Many filers run into the same issues during testing. Watch out for:

1. Invalid XML structure. Missing required elements or incorrect nesting will cause immediate rejection. Validate your XML against the IRS schema before submitting.
2. Using real TINs in test files. ATS requires test TINs starting with three zeros. Real TINs will be rejected.
3. Name field formatting errors. Submitting combined names (e.g., "John Smith" in a single field) instead of separate first/last name elements.
4. Incorrect UTID generation. Each transmission needs a unique identifier in the correct format.
5. Waiting too long to test. If you start testing in December, you won't have time to fix issues before filing season. Start as soon as ATS opens.

Plan to complete ATS well before filing season. If issues come up during testing, you'll want time to resolve them without the pressure of approaching deadlines.

Data Quality: Get It Right Before You Submit

IRIS enforces stricter data standards than FIRE. Submissions that would have passed through FIRE may be rejected or flagged in IRIS. Here's a checklist to audit your data before filing:

• Separate name fields. No combined "First Last" fields. IRIS requires distinct elements for first name, middle name/initial, last name, suffix, and business name.
• Validate TIN formats. SSNs must be 9 digits with no dashes or spaces in the XML. EINs must follow the XX-XXXXXXX pattern. Invalid formats trigger real-time rejection.
• Standardize addresses. Use USPS-standard formatting. Remove special characters that break XML parsing (ampersands, angle brackets, non-ASCII characters).
• Check required fields. IRIS enforces required elements more strictly than FIRE. Review the schema documentation for each form type you file.
• Remove duplicates. Duplicate records for the same payee/form type will cause issues. Deduplicate before submission.

Getting your data clean before you file saves time and avoids the back-and-forth of corrections.

What IRIS Does Not Do

Setting clear expectations helps you plan:

• IRIS does not file with states. Federal filing through IRIS does not automatically satisfy state information return requirements. Check your state obligations separately.
• IRIS does not accept Publication 1220 files. You cannot upload your existing FIRE-format files to IRIS. Data must be in XML format (A2A) or CSV/manual entry (portal).
• IRIS does not support all form types yet. As of 2026, IRIS supports 1099 series and 1042-S forms. Additional form types are planned but not yet available.

Who Is Impacted Most?

While every information return filer is affected, some groups face a bigger lift:

• High-volume 1099 filers (1,000+ returns) who built custom FIRE integrations will need to rebuild for IRIS XML.
• Accounting firms with many clients must transition every client's data pipeline, not just their own.
• AP outsourcing firms that handle 1099 prep for multiple companies need to ensure their tools support IRIS across all engagements.
• Payroll processors filing 1099-NEC alongside W-2s need to separate their IRIS workflow from their existing payroll filing processes.
• Organizations filing both 1099 and 1042-S should note that IRIS now handles both form families, potentially simplifying their filing infrastructure.

What This Means for Different Filers

If you file fewer than 250 returns per batch: The IRIS Taxpayer Portal is a free, web-based option. You can manually enter return data or upload a CSV with up to 250 records per file, and submit as many files as you need. You'll need an IRIS TCC, but you won't need an API Client ID or ATS testing.

If you file 250 to 5,000+ returns: You'll likely want to use the A2A channel for efficiency. This requires an IRIS TCC, passing ATS, and updating your data pipelines to produce valid XML. If you currently rely on a vendor or software platform, confirm that they support IRIS A2A filing.

If you're a 1099 consultant serving multiple clients: The transition multiplies across every client engagement. Each client's data needs to be formatted for IRIS. If you're using software that handles the formatting, verify IRIS support. If you're building files manually or with custom tools, budget significant time for the XML conversion.

The State Filing Wrinkle

While the IRS is moving to IRIS, most states still accept (or require) the old FIRE/Publication 1220 format for state-level information return filings. This means you may need to maintain the ability to produce data in both formats: XML for federal IRIS filing and ASCII for state filing.

Check your state requirements. Some states participate in the Combined Federal/State Filing (CF/SF) program, which may simplify things. But don't assume that your IRIS filing automatically covers state obligations.

How to Prepare: Your Transition Checklist

Here's a practical checklist to get ready:

• Apply for an IRIS TCC now if you don't have one. This applies to both portal and A2A filers. (If you use a third-party transmitter like Morado, they handle this for you.)
• Confirm your software supports IRIS. Contact your vendor or check their documentation.
• Audit your data quality. Use the data quality checklist above. IRIS is stricter on name fields, TIN formatting, and required elements.
• Test in ATS. If you're filing via A2A, run your test files early once ATS opens. Review the common pitfalls listed above.
• Plan for dual formatting if you have state filing obligations that still use Publication 1220 format.
• Consider filing Tax Year 2025 through IRIS as a trial run while FIRE is still available as a backup.
• Train your team. Anyone involved in information return preparation or submission needs to understand the new system.
• Review your timeline. Don't wait until Q4 2026 to start this process.

How Morado Handles the Transition

Morado's platform already files directly to the IRS through IRIS. When you upload your data (CSVs, Excel files, W-9 PDFs), Morado handles the XML formatting, TIN validation, name field parsing, and submission through the IRIS A2A channel automatically.

You don't need to learn the XML schema, apply for your own TCC, or worry about ATS testing. Morado manages the technical complexity so you can focus on getting your data right and meeting your deadlines.

If you're currently using FIRE-based tools or manual processes, Morado can replace that workflow entirely. If you're using Sovos, Avalara, or another platform, Morado can also complement your existing setup by handling the data prep and IRIS filing while you continue using your current tools.

What Comes Next

The FIRE to IRIS transition is the biggest change to information return filing in decades. IRIS already accepts 1042-S alongside the 1099 series, and the IRS plans to expand support to additional form types, including newer forms like 1099-DA. The platform will continue to evolve.

The organizations that prepare early will have the smoothest filing seasons. Those that wait until the last minute will face compressed timelines, potential filing delays, and penalties for late submissions.

Start now. Confirm your filing method, test your workflows, and make sure your tools are ready.

---

Sources: IRS IRIS Filing Page, IRS FIRE System, IRIS TCC Application, IRS Publication 1220, Form 1042-S Instructions, IRIS Working Group Q&A (May 2025), IRIS Working Group Q&A (Feb 2025)