IRS Update: Issue Number 2026-12
The IRS has announced an upcoming testing window this October for the International Data Exchange Service (IDES). If your organization is a Foreign Filer utilizing a Transmitter Control Code (TCC) account, this is a critical opportunity to ensure your reporting pipelines are functioning perfectly before live filing deadlines.
Navigating international tax reporting requires precision, particularly when it comes to the technical requirements of XML schema generation, validation, and encrypted submissions. Here is a breakdown of what this IRS update means and how to ensure your systems are ready for the test.
What is the IDES Testing Session?
The International Data Exchange Service (IDES) is the secure gateway used to transmit encrypted tax reports to the IRS. Because these transmissions involve complex encryption and strict formatting rules, the IRS periodically opens "testing sessions."
These sessions allow financial institutions and transmitters to submit test files to verify that their encryption keys are working, their digital certificates are valid, and their system connections are properly configured. Identifying technical errors during a testing window prevents stressful delays or rejected filings when submitting official data.
Exact dates for this October testing session have not been released yet, but they will be posted on the official IRS IDES Testing Schedule web page soon.
Who Can Participate in the October Test?
The IRS is strictly limiting this test session to Foreign Filer TCC Account users who have completed their IDES enrollment before the testing window opens.
You cannot simply jump into the testing environment at the last minute. To be considered fully enrolled and eligible to test, you must meet two criteria:
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Active Account: Your IDES account must be fully activated. Registration Guide Here.
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Valid Digital Certificate: You must have a valid digital certificate attached to your account. (Remember, as noted in previous updates, IDES only accepts certificates from IRS-approved Certificate Authorities).
Crucial Prerequisites: Do You Have Your TCC?
If you are new to the filing process or setting up a new entity, you cannot enroll in IDES without completing preliminary registration steps.
Before you even touch IDES, you must complete your registration on the IRS portal to obtain a TCC GIIN (Global Intermediary Identification Number for Transmitters) and explicitly request a Foreign Filer Transmitter Control Code (TCC).
Only after these are issued can you proceed to set up the digital certificates and enroll in IDES.
Action Plan for October
With the testing window approaching, you should begin technical preparations now:
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Verify Enrollment: Log in and confirm your IDES account is active and your digital certificate is linked and has not expired.
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Test Your Payloads: Review your internal workflows for generating and validating compliant XML payloads. Ensure your encryption processes align with the latest IRS guidelines.
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Watch for Dates: Monitor the IRS IDES Testing Schedule page for the official October start date.
Taking advantage of this testing window ensures your data pipelines are robust, secure, and fully compliant when it matters most.
