The FIRE to IRIS transition is the most consequential change to IRS electronic filing in over three decades. Every organization that submits information returns electronically needs to understand the FIRE to IRIS transition timeline, because the legacy Filing Information Returns Electronically (FIRE) system shuts down permanently on December 31, 2026. RegTech firm Comply Exchange has been vocal about the urgency, warning that withholding agents and compliance teams should start planning right now rather than waiting until the final months.
This is not a routine software update. It represents a fundamental shift in how the IRS receives, validates, and processes electronic information returns. Organizations that fail to prepare risk missing critical filing deadlines in 2027 and beyond.
FIRE to IRIS Transition Timeline and Key Deadlines
The IRS has laid out a clear roadmap for the FIRE to IRIS transition. During the 2026 filing season, both systems will run simultaneously. This dual-operation window gives filers a chance to test their workflows on IRIS while still relying on FIRE as a safety net. Starting in filing season 2027, IRIS becomes the only intake system for electronic submissions of Form 1099 and Form 1042-S.
That means filers have roughly nine months to familiarize themselves with the new platform, obtain the necessary credentials, and overhaul internal processes. The overlap period is not a luxury. It is a testing window that compliance teams should treat as a dry run for full migration.
One deadline that catches many organizations off guard involves the Transmitter Control Code (TCC). Existing FIRE TCCs will not carry over to IRIS. Obtaining a new TCC through the IRS e-Services portal can take up to 45 days, so organizations that delay this step could find themselves locked out when it matters most.
Why the IRS Is Retiring the FIRE System
The FIRE system launched more than 30 years ago, and it served its purpose during an era of lower filing volumes and simpler data requirements. The platform was built for a world that no longer exists. As 1099Pro has documented, FIRE ran on mainframe architecture that could not keep pace with modern security standards or the growing need for real-time processing. As the volume of information returns has grown and reporting obligations have become more complex, FIRE has struggled to keep pace.
The FIRE to IRIS transition addresses these limitations head-on. IRIS, or the Information Returns Intake System, was engineered from the ground up to handle modern reporting demands. It supports higher submission volumes, faster processing, and more flexible data intake methods. The IRS has processed millions of information returns through IRIS since its introduction in 2023, proving that the new platform can handle the load.
This retirement also aligns with a broader push toward regulatory modernization in financial services. Governments and agencies worldwide are moving away from legacy infrastructure, and the IRS is following that same trajectory.
What IRIS Brings to Electronic Filing
The old FIRE system forced filers into a single submission method: uploading files in a specific text format. IRIS changes that completely by offering multiple submission routes.
Smaller filers can use a web portal designed for straightforward, lower-volume submissions. Software providers and large-volume filers gain access to an application-to-application (A2A) transmission channel that integrates directly with their existing systems. Additional options include approved reporting platforms and commercial tax software solutions.
This flexibility is significant for organizations managing the FIRE to IRIS transition. Rather than retrofitting every workflow to match a rigid format, compliance teams can choose the submission path that fits their operational setup. That alone reduces friction and lowers the risk of errors during the migration period.
The forms affected by the FIRE to IRIS transition cover the entire 1099 series, including Form 1099-MISC, 1099-NEC, and 1099-INT, among others. The IRS has also extended IRIS to accept Form 1042-S submissions, with electronic filing available starting January 1, 2026 for returns due on March 15, 2026. Legal analysts at Ice Miller have noted that IRIS also imposes new submission constraints, including a 250-return limit per CSV file for portal users and a 100 MB cap per A2A transmission.
Real-Time Validation Changes Everything
Perhaps the biggest operational upgrade in the FIRE to IRIS transition is real-time data validation. Under FIRE, filers submitted their returns and then waited hours or even days to learn whether the IRS accepted or rejected them. That lag created uncertainty, delayed corrections, and often forced last-minute scrambles during peak filing periods.
IRIS validates submissions at the moment they arrive. Formatting errors, missing fields, and data discrepancies get flagged instantly. A recent Sovos webinar found that 31% of attendees cited understanding the technical details of IRIS as their biggest challenge, while another 25% were unsure whether their source systems could even support the new requirements. For compliance teams accustomed to batch processing and delayed feedback loops, this shift raises the operational bar considerably.
Real-time validation also means that data quality must be airtight before submission. Vendor details, account holder information, and tax documentation all need to be accurate and complete on the first pass. Under the old model, organizations could catch and correct errors after submission. That safety net disappears with IRIS.
This new standard of data accuracy aligns with broader RegTech trends across the industry, where automation and real-time processing are replacing manual, after-the-fact corrections.
5 Steps Filers Must Complete for the FIRE to IRIS Transition
Comply Exchange and other RegTech analysts have outlined specific actions that organizations should take now. Here are the five most critical steps for managing the FIRE to IRIS transition successfully.
First, apply for a new Transmitter Control Code immediately. The 45-day processing window means that organizations applying in late 2026 risk missing their filing deadlines entirely. Do not assume that your existing FIRE TCC will work on IRIS. It will not.
Second, audit your data quality. Real-time validation will reject submissions with incomplete or inaccurate information. Run a full review of vendor records, taxpayer identification numbers, and account holder details before you attempt your first IRIS submission.
Third, test your workflows during the 2026 dual-operation window. Submit test files through IRIS while FIRE is still available as a backup. Identify integration issues, formatting gaps, and process bottlenecks before the safety net vanishes.
Fourth, evaluate your submission method. Determine whether the web portal, A2A channel, or a third-party platform best suits your organization’s volume and technical capabilities. Choosing the wrong path creates unnecessary friction during an already complex transition.
Fifth, train your team. The FIRE to IRIS transition is not just an IT project. Every person involved in information return preparation, review, and submission needs to understand the new platform’s requirements and validation standards.
How RegTech Firms Are Preparing for the Shift
The FIRE to IRIS transition has created a surge of activity among compliance-focused fintech and RegTech firms. Comply Exchange, for example, has published detailed migration guides and is offering consulting services to help organizations navigate the changeover.
Other firms are building IRIS-compatible modules into their existing tax reporting software, ensuring that clients can switch submission methods without overhauling their entire tech stack. This kind of vendor support will be essential for mid-market organizations that lack dedicated in-house compliance engineering teams.
The RegTech sector views the FIRE to IRIS transition as both a challenge and an opportunity. Firms that move quickly to support IRIS adoption will earn long-term client loyalty, while those that lag behind risk losing relevance as the December 2026 deadline approaches.
What Happens If You Miss the Deadline
Organizations that fail to complete the FIRE to IRIS transition before January 2027 will not have a functioning electronic submission channel for information returns. FIRE will be offline. There is no extension, no workaround, and no manual fallback for large-volume filers. As Tab Service Company has outlined, returns originally filed through FIRE still require corrections through FIRE even after the system retires, which means organizations may need to maintain access to both systems during a transition period just to handle prior-year amendments.
Late compliance could result in IRS penalties for missed filing deadlines, reputational damage with business partners and clients, and operational chaos during tax season. The cost of inaction far exceeds the cost of preparation.
The FIRE to IRIS transition is happening whether organizations are ready or not. The only variable is whether your team invests the time now to ensure a smooth migration, or scrambles to catch up when it is already too late.