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The Ultimate Guide to Criminal Tax Defense

By
Venar Ayar, JD, LLM (Tax)
on
January 26, 2026

Dealing with the IRS Criminal Investigation Division: What Taxpayers Need to Know

With a conviction rate consistently above 90%, a notice from an IRS-CI special agent signals a shift from a civil dispute over tax liability to a federal criminal case where your freedom is on the line. If you’re facing a criminal tax investigation, you need to know how the federal law enforcement branch of the Internal Revenue Service functions. The words “IRS” and “investigation” in the same sentence can stop anyone cold. Add “criminal” to the mix, and the stakes become life-altering.

Our comprehensive guide explains what the IRS Criminal Investigation division (IRS-CI) is, how it operates, and what taxpayers need to know regarding criminal defense to protect themselves from potentially devastating consequences.

The IRS Criminal Investigation Division

Official Mission and Authority

IRS Criminal Investigation serves as the federal government’s primary agency responsible for investigating potential criminal violations of the Internal Revenue Code. IRS-CI operates as a full-fledged federal law enforcement agency with significant powers. IRS-CI special agents aren’t tax collectors. They carry badges and weapons and have the authority to make arrests.

Core Responsibilities

IRS-CI concentrates on three primary areas:

  • Investigate potential criminal violations, including tax evasion, filing false tax returns, and willful failure to file returns
  • Pursue financial crimes such as money laundering, tax fraud, and Bank Secrecy Act violations
  • Target related criminal activities involving narcotics trafficking, terrorism financing, and public corruption with financial components

Position in Federal Law Enforcement

IRS-CI holds exclusive jurisdiction over criminal violations of the Internal Revenue Code, including federal tax fraud. This exclusivity makes their expertise invaluable to other federal agencies like the FBI, DEA, and Homeland Security.

Their high conviction rate demonstrates both their selectivity in pursuing cases and their thoroughness in conducting IRS criminal investigations, making it crucial for individuals to consult with criminal tax defense lawyers. When IRS-CI commits resources to a criminal tax investigation, they typically have substantial evidence before making their presence known.

IRS-CI Structure and Organization

Understanding how IRS-CI operates provides insight into its approach to criminal investigations.

The agency operates under the leadership of the Chief of Criminal Investigation, Guy Ficco, who reports to the Internal Revenue Service Commissioner. The organization maintains 20 field offices across the United States, with each field office supported by smaller resident agencies serving local jurisdictions.

Internationally, IRS-CI maintains attachés in strategic locations worldwide to combat global financial crimes and support cross-border criminal investigations.

The IRS-CI workforce includes approximately 2,100 special agents supported by 3,000 total employees, including technical specialists and administrative staff. These agents undergo extensive training in financial investigation techniques, criminal law, and firearms use.

IRS-CI Powers and Authority

Law Enforcement Powers

Under 26 USC 7608, the IRS-CI special agents possess full federal law enforcement authority. They can make arrests, execute search warrants, carry firearms, and serve grand jury subpoenas. They remain the only IRS employees authorized to carry weapons, underscoring their distinct role from civil tax collectors.

Criminal vs. Civil IRS Functions

Civil functions focus on examining tax returns and collecting tax revenue, while criminal functions focus on punishing willful violations and deterring others from committing similar offenses. Civil cases require a “preponderance of evidence,” while criminal cases demand proof “beyond a reasonable doubt.” Criminal investigations trigger Miranda rights and other criminal procedures designed to safeguard your rights.

How Cases Transition from Civil Matters to a Criminal Tax Investigation

When a civil audit or collection case reveals indicators of tax fraud, the IRS revenue officer or revenue agent may complete a Form 2797; this is an official referral to the Criminal Investigation Division.

IRS-CI will evaluate if there is a “firm indication of fraud”. If and when IRS-CI accepts a case, civil proceedings typically freeze while the criminal investigation proceeds, often without the taxpayer’s knowledge. We’ve seen many clients make critical mistakes during this transition period, unwittingly providing damaging information because they didn’t recognize the shift from civil to criminal focus.

IRS-CI Investigation Priorities

IRS-CI concentrates its limited resources on high-impact areas:

  • Unreported income, false deductions, and hiding assets
  • Financial crimes like money laundering and Bank Secrecy Act violations
  • International tax fraud involving offshore accounts, foreign income concealment, and FBAR violations
  • Identity theft and refund fraud through organized schemes to file fraudulent tax returns

Emerging Areas of Focus

In 2025, IRS-CI intensified scrutiny of:

  • Cryptocurrency transactions involving unreported gains, mining income, and exchange reporting
  • Professional tax preparers who facilitate false claims and operate return mills
  • High-net-worth individuals implementing complex schemes involving multiple entities
  • Cyber financial crimes, including online fraud schemes and digital evidence

The Role of Other Agencies

Department of Justice Relationship

IRS-CI works closely with the Department of Justice Tax Division, which must approve all tax-related prosecutions. After investigation, IRS-CI refers cases to the DOJ Tax Division for evaluation and U.S. Attorneys’ offices for prosecution.

Multi-Agency Task Forces

IRS-CI participates in numerous task forces:

  • Organized Crime Drug Enforcement Task Force (OCDETF) targeting the financial aspects of drug trafficking
  • Joint Chiefs of Global Tax Enforcement (J5) focusing on international partnership targeting cross-border tax crimes
  • Financial Crimes Enforcement Network (FinCEN) is collaborating on Bank Secrecy Act enforcement

International Cooperation

Global financial crimes require global responses. IRS-CI leverages tax treaty information exchange provisions, foreign government partnerships, and joint investigations with international counterparts.

This cooperation has significantly expanded IRS-CI’s ability to pursue offshore tax evasion and international financial crimes. Our tax attorneys have handled numerous cases involving international tax compliance issues, helping clients navigate voluntary disclosure programs to avoid criminal prosecution.

What This Means for Taxpayers

When IRS-CI Gets Involved

The IRS-CI focuses on the IRS criminal investigation process by pursuing cases involving substantial violations, demonstrating willful conduct (i.e., knowing and intentional violations), and offering a strong deterrent value.

The agency doesn’t pursue simple mistakes or negligence. They target deliberate attempts to evade tax obligations through affirmative acts like concealing income, creating false documents, or making false statements.

Impact on the Tax System

The criminal enforcement function serves several purposes:

  • Deters would-be tax criminals through visible prosecutions
  • Maintains public confidence in the fairness of the tax system
  • Encourages voluntary compliance by demonstrating consequences

Key Takeaways and Next Steps

The involvement of the IRS Criminal Investigation Division signals potential criminal charges with life-altering consequences, including prison time, substantial fines, and lasting reputational damage.

Understanding IRS-CID’s mission, methods, and priorities provides context for recognizing when a tax matter may have crossed from civil to potential criminal violations. If you believe you’re under investigation or at risk, consult with a qualified criminal tax defense attorney immediately. Protecting your rights requires extensive knowledge of both tax law and criminal procedure.

Our tax law firm understands the in-depth knowledge required to navigate complex criminal tax cases and achieve the best possible outcomes in these high-stakes situations. 

Help for Criminal Tax Defense

If you’re concerned about a potential criminal tax investigation for tax evasion or tax fraud, contact our experienced criminal tax defense team for a confidential case review. We can help you develop an effective strategy to protect your freedom, finances, and future. Our experienced tax attorneys are standing by, ready to to help.

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About the Author

Attorney Venar Ayar is an award-winning tax attorney dedicated to helping clients protect themselves from the constant threat of the IRS. Whether you need help with unfiled tax returns, applying for an Installment Agreement, settling for less than you owe through the OIC program, or some other form of IRS debt relief, we’ve got you covered.
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