IRS Issues Formal Guidance on AI, Reminding Tax Professionals They Retain Full Responsibility

WASHINGTON — The Internal Revenue Service on June 25, 2026, issued new guidance clarifying the role of artificial intelligence in tax preparation, formally reminding tax professionals that they remain solely responsible for the accuracy of returns and cannot delegate their professional judgment to automated systems.

The announcement serves as a direct caution to the rapidly growing number of accountants, enrolled agents, and tax attorneys incorporating AI tools into their practices. It emphasizes that while AI can be a powerful asset for efficiency and data analysis, it does not absolve practitioners of their fundamental duties under Treasury Department Circular 230, the regulations governing practice before the IRS.

“The use of AI can be a valuable tool for tax professionals, but it cannot replace the professional’s ultimate responsibility for the accuracy of a tax return,” the guidance stated. Practitioners are expected to exercise due diligence, which the IRS clarified includes critically evaluating and independently verifying any output from an AI system before it is used in a client’s tax filing.

This move comes amid a proliferation of AI-powered software marketed to accounting and tax firms, promising to streamline complex workflows, automate data entry, and even provide initial interpretations of tax law. The IRS appears to be proactively establishing guardrails to prevent over-reliance on a technology that, while advanced, is still prone to errors, biases in its training data, and so-called “hallucinations,” where the AI generates confident but entirely fabricated information.

For the small and mid-sized businesses that depend on these professionals, the IRS’s stance reinforces the critical importance of the human element in their financial compliance. An error on a business tax return, whether generated by a human or an AI, can trigger significant consequences, including substantial underpayment penalties, interest charges, and disruptive, time-consuming audits. The guidance makes it clear that a practitioner attempting to blame an AI tool for a mistake would not have a valid defense.

The IRS's statement directly addresses the crucial issue of liability. If an AI tool misinterprets a complex regulation regarding, for example, inventory valuation under LIFO vs. FIFO, or fails to identify a niche tax credit available to a specific industry, the practitioner who signs and files the return is the one held accountable by the agency, not the software developer.

Beyond accuracy, the guidance also implicitly touches on data privacy and security. Tax professionals handle a vast amount of sensitive client financial data. The use of third-party AI platforms, particularly those that use client data to train their models, raises significant questions about how that information is stored, processed, and protected from potential breaches. The IRS expects practitioners to conduct thorough due diligence on the security protocols and data handling policies of any AI vendor they engage, ensuring compliance with federal and state privacy laws.

Under Circular 230, professionals have a duty to exercise competence and diligence. The new guidance suggests that competence in the modern era now includes a sophisticated understanding of the AI tools being used. This means practitioners must be aware of their limitations and build robust internal review processes to catch potential errors. This presents a challenge with some of the more advanced or opaque “black box” AI models, where it can be difficult to trace exactly how the system arrived at a particular conclusion, making independent verification a more demanding task.

In our experience, while AI tools can accelerate research and data organization, they are not a substitute for the nuanced strategic thinking required for effective business tax planning. We've seen how generic AI models can miss industry-specific deductions or fail to grasp the interplay between federal, state, and local tax obligations for a growing business. The IRS's reminder is a crucial one: technology should serve the expert, not replace them. A business owner's financial health is too important to entrust to an algorithm that cannot be held accountable. This is why our approach to tax preparation and compliance integrates best-in-class technology with the indispensable oversight of seasoned professionals. For businesses seeking confidence that their tax strategy is both compliant and optimized, human judgment remains the most valuable asset. If you have concerns about how these issues affect your business, the team at C&S Finance Group LLC at csfinancegroup.com is prepared to help.

Following this announcement, tax professionals and industry associations are expected to move quickly to develop and codify best practices for the ethical and competent use of AI. Software developers will also likely face increased market pressure to build more transparency and auditability into their AI-powered products. For now, businesses should feel empowered to ask their tax advisors about the role AI plays in their firm's processes and the specific safeguards in place to ensure accuracy and protect their data, as the IRS has signaled this will be an area of future focus.