If you work in tax operations at a bank, credit union, or brokerage, you already know that the FIRE system shuts down on December 31, 2026. What you might not fully appreciate yet is how uniquely difficult this transition is for financial institutions – and how little runway you have left.
Banks aren’t filing 200 1099-NECs for contractors. They’re filing tens of thousands – sometimes hundreds of thousands – of 1099-INTs, 1099-DIVs, 1099-Bs, and 1099-OIDs. Every account holder with more than $10 in interest gets a form. That volume creates challenges that don’t apply to typical businesses, and those challenges compound when you’re migrating from a flat-file system to XML in the middle of a regulatory calendar that doesn’t pause for infrastructure projects.
This is your timeline and action plan.
Why Banks Face a Harder Migration
Most businesses filing 1099s interact with them once a year. Generate the file, upload it, move on. Financial institutions live in a different world. The FIRE-to-IRIS migration hits banks harder for four reasons that compound on each other.
1. Volume Amplifies Every Problem
A community bank with 30,000 deposit accounts might generate 25,000 1099-INTs. A regional bank could file 200,000+. National institutions file millions. At those volumes, every schema validation error, every XML formatting issue, every API timeout becomes a systemic problem rather than an isolated fix.
With FIRE, a single flat file could contain your entire filing. With IRIS, you may need to batch submissions, handle rate limits, manage submission receipts for each batch, and build retry logic for failures – none of which existed in your FIRE workflow.
Note: Large entities (gross receipts over $5 million) have no penalty cap under IRC Section 6721. A bank with 100,000 late filings at $310 each faces $31 million in potential penalties.
2. Mainframe and Core Banking Dependencies
Many banks generate their FIRE files from core banking systems that run on mainframes or legacy platforms. These systems have been producing Publication 1220 flat files – sometimes for decades. The output routines are deeply embedded in batch processing jobs that run on fixed schedules, often as part of year-end processing cycles that also handle statement generation, regulatory reporting, and account reconciliation.
Changing the output format of a core banking system isn’t a simple configuration change. It typically requires:
- Vendor engagement if the core system is third-party (most are)
- COBOL or RPG code modifications for in-house systems
- Regression testing across the entire year-end batch cycle
- Change management approval, which in banking can take weeks
- Coordination with auditors and compliance teams
If your core banking vendor hasn’t published their IRIS roadmap yet, that’s a red flag you need to escalate immediately.
3. Multi-Form Complexity
Unlike most businesses, banks file multiple 1099 variants simultaneously. A typical bank filing run includes:
- 1099-INT – Savings accounts, CDs, money market accounts, interest-bearing checking
- 1099-DIV – Mutual fund dividends, REIT distributions, capital gains distributions
- 1099-B – Securities transactions, cost basis reporting, covered/noncovered lots
- 1099-OID – Original issue discount on bonds and CDs
- 1099-MISC/NEC – Vendor payments, referral fees, prizes and awards
- 1099-R – IRA distributions, pension payments
- 5498 – IRA contributions
Each form type has its own XML schema under IRIS. Each needs separate validation, testing, and submission handling. A migration that handles 1099-INT but hasn’t been tested with 1099-B (which has significantly more complex data structures for cost basis reporting) isn’t a complete migration.
4. Regulatory Scrutiny
Banks operate under examination by the OCC, FDIC, Federal Reserve, or state regulators. A failed filing – even a late one – shows up in regulatory examinations. It triggers questions about operational risk management. It can affect examination ratings. The stakes for getting this wrong extend well beyond IRS penalties into the regulatory framework that governs your institution’s operating authority.
The Bank IRIS Migration Timeline
Here’s a realistic timeline for financial institutions. Note that this isn’t aspirational – it’s the minimum you need to hit each milestone without creating crisis conditions in Q4.
August-September 2026: Assessment and Vendor Alignment
- Audit your current FIRE process end to end. Document every system that touches the filing pipeline – core banking, data warehouse, file generation, transmission, reconciliation. Identify who owns each step.
- Contact your core banking vendor. Get their IRIS timeline in writing. Ask specifically: Will your system produce IRIS-compatible XML output by November? If not, what’s the workaround?
- Evaluate your path. There are three options: (1) your core vendor adds XML output, (2) you build a conversion layer in-house, or (3) you use a filing provider that accepts your existing FIRE-format output. Most banks will use option 1 or 3.
- If you need a new TCC, apply now. The 45-day processing window means an August application gets approved in September/October, leaving time for testing. A November application is a gamble.
October 2026: Build and Test
- Generate test XML from production-like data. Use prior-year data to create realistic test submissions. Include edge cases: foreign addresses, backup withholding, exempt payees, multi-TIN accounts.
- Test every form type you file. 1099-INT working does not mean 1099-B works. Test each variant independently.
- Validate at volume. Processing 100 test records tells you nothing about how the system handles 100,000. Test at or near production volume.
- Verify your correction workflow. Corrections through IRIS use a different process than originals. Test corrections before you need to use them in February.
November 2026: Parallel Run
- Run your year-end batch processing in parallel. Generate both FIRE-format output (for comparison) and IRIS XML output. Reconcile the two. Every discrepancy is a bug to fix before January.
- Submit test filings through the IRIS sandbox. Confirm that what your system produces is what IRIS accepts.
- Finalize your fallback plan. If your primary approach isn’t working by November 30, you need to activate Plan B. For most banks, Plan B is a filing provider. Get the account set up now so activation is instant.
December 2026: Lock and Load
- Finalize year-end data. Run standard year-end closing procedures.
- Generate production IRIS filings. Validate against the schema one final time.
- FIRE shuts down December 31. There is no extension.
January 2027: File
- Submit through IRIS. Monitor for rejections and errors.
- Distribute recipient copies. Deadline: January 31 for 1099-INTs, February 15 for 1099-Bs and 1099-DIVs.
- File with the IRS. E-filing deadline: March 31 (or February 28 for paper, but banks file electronically).
The FIRE File Advantage
Here’s the detail many banks miss when evaluating their migration options: you don’t have to change your file output at all.
Your core banking system generates FIRE-format flat files. It has generated them reliably for years. The data in those files is accurate, tested, reconciled, and audited. The only thing changing is the IRS’s intake format.
A filing provider like BoomTax accepts your FIRE-format files directly and converts them to IRIS XML automatically. Your core banking system, your batch processes, your reconciliation reports – none of it changes. The FIRE file is the input; IRIS XML is what gets submitted to the IRS. BoomTax handles the conversion.
For banks facing vendor uncertainty or tight timelines, this is the fastest path to compliance. Keep producing the files you’ve always produced. Let the conversion happen downstream.
Batch Processing Considerations
FIRE accepted a single file upload per transmission. You could package your entire filing – 100,000 1099-INTs – into one file and transmit it in a single session. IRIS doesn’t work the same way.
If you’re building a direct IRIS integration, you need to plan for:
- Submission size limits. IRIS may impose limits on the number of records per submission or the file size per upload.
- Asynchronous processing. Unlike FIRE’s synchronous acknowledgment, IRIS processes submissions asynchronously. You submit, receive a receipt, and poll for status. Your system needs to handle the delay.
- Partial rejections. A batch might partially succeed. Your system needs to identify which records were accepted and which need resubmission.
- Rate limiting. API-based submissions may have rate limits that affect how quickly you can submit high volumes.
- Error categorization. Some errors are retryable (timeouts, rate limits), others require data fixes (schema validation failures). Your batch processor needs to distinguish between them.
For the complete technical reference on these differences, see the FIRE-to-IRIS transition timeline.
What About Corrections?
Banks file a disproportionate number of corrections. Account holder name changes, TIN corrections from B-Notices, amount adjustments after year-end – these are routine in banking. Under FIRE, corrections used the same flat-file format with a corrected indicator. Under IRIS, the correction process uses different XML structures and potentially different API endpoints.
Your migration plan must include corrections. If you’re testing only original submissions, you’ll discover the gap in February when B-Notice corrections start flowing and your IRIS correction workflow hasn’t been built yet.
Frequently Asked Questions
Our core banking vendor says IRIS support is “on the roadmap.” Is that enough?
No. “On the roadmap” means it isn’t built yet. You need three things from your vendor: (1) a committed delivery date, (2) a list of which form types will be supported at launch, and (3) a testing timeline. If any of those are vague, you need a parallel plan. The safest parallel plan is a filing provider that accepts your current FIRE output.
Can we file 1099-INTs on paper if IRIS isn’t ready?
Technically, yes – but practically, no. If you file 250 or more returns of any type, the IRS requires electronic filing. Every bank exceeds that threshold for 1099-INT. Filing on paper when you’re required to file electronically triggers penalties of $60-$310 per form. For a bank filing 50,000 1099-INTs, the minimum penalty would be $3 million.
Do we need a separate TCC for IRIS if we already have a FIRE TCC?
Yes. FIRE TCCs do not transfer to IRIS. If you plan to file directly with the IRS through IRIS, you need a new IRIS TCC. If you use a filing provider like BoomTax, you don’t need one – the provider files under their TCC on your behalf.
What about 1099-B cost basis reporting? That data structure is significantly more complex.
1099-B is the most complex form in the IRIS migration because of lot-level cost basis detail, covered/noncovered designations, wash sale adjustments, and date-acquired fields. If your institution files 1099-Bs, this form type should be your first testing priority – not your last. Validate the XML schema against real transaction data, not synthetic samples.
Our filing volume is over 500,000. Can a provider handle that?
BoomTax handles high-volume filing for financial institutions. The platform is built for batch processing at scale – upload your FIRE-format file, and the system parses, converts, validates, and submits to IRIS. Whether you’re filing 5,000 or 500,000 forms, the process is the same. See the banking-specific filing guide for details on volume handling and SLAs.
Your Action Items for This Week
You’ve read the analysis. Here’s what to do with it.
- Today: Email your core banking vendor and ask for their IRIS delivery date and supported form types. Get it in writing.
- This week: Inventory every 1099 form type your institution files. Map each to the system that generates it.
- This month: Make the build-vs-buy decision for each form type. If your vendor won’t deliver XML output in time, establish a provider relationship now.
- By end of September: Have your testing plan in place. Know what you’re testing, with what data, against which environment.
For a comprehensive view of the entire transition, see the IRS IRIS complete guide.
Create your free BoomTax account and upload a test file today. See the conversion in action before you commit to anything. It takes 15 minutes – and it might save your institution months of development work.
BoomTax, The Boom Post, and its affiliates do not provide tax, legal or accounting advice. This material has been prepared for informational purposes only, and is not intended to provide, and should not be relied on for, tax, legal or accounting advice. You should consult your own tax, legal and accounting advisors prior to engaging in any transaction.
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