IRS Pub 5718 – IRS Forms, Instructions, Pubs 2026 – In the ever-evolving landscape of tax compliance, the IRS continues to modernize its systems to streamline electronic filing for information returns. IRS Publication 5718 serves as the definitive resource for the Information Returns Intake System (IRIS) Application-to-Application (A2A) specifications. This guide breaks down everything you need to know about Pub 5718, including its purpose, key updates for Processing Year 2026, technical requirements, and how it impacts filers. Whether you’re a software developer, transmitter, or issuer, understanding these specifications is crucial for efficient and compliant e-filing.
What is IRS Publication 5718?
IRS Publication 5718 outlines the technical and procedural guidelines for electronically filing information returns through the IRIS A2A system. Released in its latest revision (Rev. 1-2026) on February 4, 2026, this document focuses on using Extensible Markup Language (XML) for bulk submissions, ensuring secure and accurate transmission of large volumes of data. It covers communication protocols, validation processes, error handling, corrections, and participation in the Combined Federal/State Filing (CF/SF) program.
The publication is essential for entities required to file 10 or more information returns annually, as mandated by recent IRS regulations. Unlike the older Filing Information Returns Electronically (FIRE) system, IRIS A2A offers modern features like real-time validation, API integration, and support for a broader range of forms.
Key Purpose and Scope
- Electronic Filing Framework: Details how to submit transmissions directly from your application to IRIS using REST APIs over HTTPS.
- Supported Tax Years: Primarily for Tax Year 2025 filings in Processing Year 2026, with provisions for prior years.
- Transmission Limits: Up to 100 MB per transmission, with each containing a manifest and multiple submissions of the same form type.
You can download the full PDF of IRS Publication 5718 directly from the official IRS website: https://www.irs.gov/pub/irs-pdf/p5718.pdf.
Understanding the IRIS A2A System
The IRIS A2A channel is designed for high-volume filers, allowing automated submissions via XML format. It replaces manual processes with application-to-application connectivity, making it ideal for third-party software providers and large issuers.
How IRIS A2A Differs from Other Filing Methods?
- Vs. IRIS Taxpayer Portal: A2A is for bulk filing (thousands of returns), while the portal suits smaller volumes with manual entry or CSV uploads.
- Transition from FIRE: IRIS uses modern XML schemas for better flexibility, security, and data granularity (e.g., separate name fields). FIRE will be retired after Tax Year 2025.
Supported Forms in Pub 5718
For Tax Year 2025, IRIS A2A supports an expanded list of forms, including:
| Form Type | Examples |
|---|---|
| 1042 Series | 1042-S, 1042-T |
| 1097/1098 Series | 1097-BTC, 1098, 1098-C, 1098-E, 1098-F, 1098-Q, 1098-T |
| 1099 Series | 1099-A, 1099-B, 1099-C, 1099-CAP, 1099-DA, 1099-DIV, 1099-G, 1099-INT, 1099-K, 1099-LS, 1099-LTC, 1099-MISC, 1099-NEC, 1099-OID, 1099-PATR, 1099-Q, 1099-QA, 1099-R, 1099-S, 1099-SA, 1099-SB |
| Other Forms | 3921, 3922, 5498, 5498-ESA, 5498-QA, 5498-SA, W-2G |
Transmittal forms like 1096 are embedded in submission headers.
Key Updates in the 2026 Revision of Pub 5718
The latest version includes several enhancements to improve accuracy and functionality:
- New Forms Added: Inclusion of 1042-S, 1099-DA, and 5498-QA; removal of 1099-H.
- CF/SF Program Changes: Rhode Island added as a participant; Missouri removed.
- Schema and Business Rules: Updated version numbers (e.g., TY2025 v2.0); manifest elements now include VersionNum and VersionDt.
- Clarifications: Enhanced details on TCC issuance, EIN matching, API access, and validation processes.
- Due Dates Expanded: Chart now covers more forms for timely filing.
Software developers are encouraged to retest updates using the IRIS Assurance Testing System (ATS), which opens annually in November.
Technical Specifications and Requirements
Registration and Authentication
To use IRIS A2A:
- Register via IRS e-Services with ID.me credentials.
- Apply for an IRIS Transmitter Control Code (TCC) through the IRIS Application for TCC.
- Obtain an API Client ID for authentication.
Authentication uses OAuth 2.0 with JSON Web Tokens (JWT) and JSON Web Key Sets (JWKS), requiring RSA-signed certificates. Tokens expire after 15 minutes.
XML Structure and Validation
- Unique Identifiers: Include Unique Transmission ID (UTID), Submission ID (SID), and Record ID (RID).
- Transmission Types: Original (O), Correction (C), Replacement (R).
- Validation Stages: Pre-receipt (format checks) and post-receipt (business rules).
- Prohibited Elements: Specific characters and tags are restricted to prevent errors.
Schemas and business rules are available on the IRS website and updated annually.
Error Handling, Corrections, and Replacements
- Acknowledgments: Retrieve status (Accepted, Rejected, etc.) using Receipt ID.
- Replacements: For partially accepted transmissions, target specific submissions with OriginalUniqueSubmissionId.
- Extensions: Automatic 30-day extensions available; additional requests via Form 8809.
Combined Federal/State Filing (CF/SF) Program
IRIS A2A supports sharing data with participating states, now including Rhode Island. This eliminates separate state filings for approved forms, simplifying compliance.
Additional Resources and Support
- Help Desk: Call 1-866-937-4130 for assistance.
- Chatbot: Available 24/7 for quick queries.
- Related Publications: Pub 5717 (Taxpayer Portal Guide), Pub 5719 (ATS Test Package).
For the most current details, always refer to the official IRS sources. Download IRS Publication 5718 here: https://www.irs.gov/pub/irs-pdf/p5718.pdf.
By staying compliant with these specifications, filers can avoid penalties and ensure smooth processing. If you’re transitioning from FIRE, start testing with IRIS ATS today to prepare for 2026 filings.