IRS IRIS Publications 5717, 5718, 5719 & 5903

Which IRIS Publication Do You Need?

IRS resource	What it covers	Who should use it
Publication 5717	IRIS Taxpayer Portal user guide: manual entry, CSV upload, recipient copies, extensions, and corrections	Businesses and practitioners filing through the browser-based portal
Publication 5718	IRIS A2A electronic-filing specifications, XML requirements, transmissions, replacements, and corrections	Software developers, transmitters, service bureaus, and enterprise integration teams
Publication 5719	IRIS Assurance Testing System (ATS) test package and testing requirements	A2A software developers and transmitters preparing for production access
Publication 5903	Step-by-step IRIS Application for TCC tutorial	Organizations applying for or updating an IRIS TCC

The remainder of this guide focuses on Publication 5718, the resource needed to build a direct IRIS A2A integration.

What Is Publication 5718?

IRS Publication 5718 is the official technical reference document for the IRIS A2A (Application-to-Application) API. It is the IRIS equivalent of what Publication 1220 was for FIRE — the definitive specification that developers need to build software that communicates directly with the IRS filing system.

Pub 5718 is published by the IRS and updated as IRIS evolves. It describes the A2A transmission format, SOAP services, authentication, receipts, acknowledgments, replacements, and corrections, and it works with the separately published schemas and business rules. It is a technical document aimed at software developers and system integrators — not at end users or tax preparers.

Who Needs to Read Publication 5718?

The short answer: only developers building direct IRIS integrations. This includes:

• Tax software developers building IRIS filing capabilities into their products
• Enterprise IT teams developing custom A2A integrations for their organization's filing pipeline (see our enterprise IT migration guide)
• Service bureau engineers building IRIS transmission capabilities into filing platforms
• ERP integration developers connecting payroll, AP, or HR systems to IRIS

If you are a tax preparer, CPA, payroll provider, or small business owner, you do not need to read Pub 5718. You can use the IRIS Taxpayer Portal, the CSV upload feature, or a filing provider like BoomTax to file without ever touching the A2A API.

Key Sections of Publication 5718

Pub 5718 is organized into several major sections. Here is what each covers and why it matters:

Authentication and Authorization

Before your application can submit data to IRIS, it must authenticate. Pub 5718 defines the authentication flow, which involves:

• e-Services account credentials — The organization must have a registered IRS e-Services account
• IRIS TCC (Transmitter Control Code) — A separate authorization that identifies the organization transmitting through A2A. The IRS says a typical TCC application is processed within 45 business days, although processing times vary.
• API Client ID and token-based authentication — A2A uses OAuth authorization with JSON Web Tokens (JWTs), an IRIS Client ID, and an authorized IRIS user identity as documented in the specification.

Understanding the auth flow is critical, as authentication failures are one of the most common issues in new IRIS integrations. The TCC differences between FIRE and IRIS are significant and worth understanding.

XML Schema Definitions

Publication 5718 and the current IRS A2A schema package define how to construct XML for the form types supported by the A2A channel. Each XSD specifies:

• Element hierarchy — The parent-child structure of the XML document
• Required vs optional elements — Which fields must be present for the submission to validate
• Data types and constraints — String lengths, numeric formats, enumerated values, and date formats
• Namespace definitions — The XML namespaces used for validation

The XML schemas are published as XSD (XML Schema Definition) files that your code can use for client-side validation before submitting to the IRS. For a higher-level overview of the XML format, see our IRIS XML format guide.

SOAP Web Service Operations

The IRIS A2A channel uses SOAP (Simple Object Access Protocol) web services, not REST APIs. This is a significant architectural choice that affects how developers build integrations. Pub 5718 defines the available SOAP operations, including:

• Submission operations — Sending one or more information returns to the IRS
• Status inquiry operations — Checking the processing status of a previous submission
• Correction operations — Submitting corrections to previously filed returns
• Acknowledgment retrieval — Retrieving IRS acknowledgments and acceptance/rejection details

Each operation has a defined WSDL (Web Services Description Language) document, request/response message formats, and fault handling specifications.

Error Codes and Validation

Pub 5718 defines the status, acknowledgment, and error-response structures used by A2A. The IRS publishes the current schemas and business rules separately, and our error codes guide explains how to interpret common validation and business-rule failures.

An accepted transport request returns a Receipt ID, but return-level processing is asynchronous. Integrations must poll for the final acknowledgment and handle Accepted, Accepted with Errors, Partially Accepted, and Rejected results.

Testing Environment and Procedures

Publication 5718 documents the A2A communication requirements, while Publication 5719 is the dedicated IRIS ATS test package. Together they cover:

• How to access the test environment
• Test TINs and data sets for validation
• Expected responses for various test scenarios
• Requirements for production certification

Software Developers must pass the applicable ATS software tests. Issuers and Transmitters using approved software complete a one-time communication test before the applicable A2A TCC indicator is moved to production.

Publication 5718 vs Publication 1220: What Changed

If your team is familiar with Publication 1220 (the FIRE specification), here is how Pub 5718 differs:

Aspect	Pub 1220 (FIRE)	Pub 5718 (IRIS A2A)
Data format	Fixed-width text (ASCII)	XML with published XSD schemas
Protocol	File upload via web portal	SOAP web services
Validation	Batch processing, delayed feedback	Receipt followed by asynchronous return-level acknowledgment
Error reporting	Generic error categories	Granular error codes with descriptions
Authentication	Username/password via FIRE web portal	Token-based API authentication
Testing	Separate test file upload process	Dedicated sandbox environment with test data

For a broader comparison of the two systems (not just the specs), see our IRIS vs FIRE comparison.

Where to Get Publication 5718

Publication 5718 is available for free from the IRS:

• IRS.gov: Search for "Publication 5718" on irs.gov or check the IRIS A2A documentation page
• IRS IRIS Developer Resources: The A2A developer portal includes the publication alongside XSD files, WSDL documents, and sample code
• Updated annually: The IRS publishes revised versions of Pub 5718 as IRIS evolves and new form types are added. Always verify you have the current version.

BoomTax Implements Pub 5718 So You Don't Have To

Building a direct IRIS A2A integration is a serious engineering effort. It requires understanding SOAP services, implementing XML schema validation, handling token-based authentication, managing error codes, and passing IRS testing certification. For most organizations, this is months of developer time that could be spent on your core business.

BoomTax has already implemented the full Pub 5718 specification. When you file through BoomTax — whether through our web interface, bulk upload, or API — BoomTax handles the IRIS A2A communication, XML generation, authentication, error handling, and status tracking. You get a simple, modern interface on top of the complex IRS infrastructure.

For organizations evaluating whether to build a direct integration or use a provider, see BoomTax vs IRIS direct filing and our IRIS API integration guide.

Frequently Asked Questions

Next Steps

• IRIS API integration guide
• IRIS testing and sandbox guide
• IRIS error codes reference
• IRIS XML format guide
• FIRE-to-IRIS migration guide for enterprise IT
• BoomTax vs IRIS direct filing