Since 1988, our attorneys have gone up against criminal enterprises, oligarchs, and major corporations. The founding attorneys at International Whistleblower Advocates are behind over one-third of all IRS whistleblower awards, with three awards over $100 million.

Our international tax whistleblower attorneys represent individuals who provide specific and credible evidence of any U.S. citizen or corporation using illegal tactics to evade paying their tax obligation, such as hiding income, falsifying records, claiming fraudulent deductions, misrepresenting residency or dependents, concealing assets, or filing improperly, among others.

If you are an individual with strong evidence of tax evasion or underpayment, get in touch with our attorneys today for a free and confidential consultation. Any individual with information of a U.S. citizen or corporation engaging in such activity can file a complaint and become eligible for an award under the IRS Whistleblower Program.

Tax Evasion Whistleblower Practice

What separates our firm from others is our renowned expertise. Not only have we fought and won numerous high-profile tax evasion cases, we’ve also been instrumental in shaping the IRS Whistleblower Program itself through IRS rulemaking.

Our efforts include filing rulemaking petitions with regulators, providing testimony at official hearings, submitting amicus curiae briefs in landmark tax whistleblower cases, and advocating for legislative reforms to strengthen the Program’s effectiveness.

Our IRS Whistleblower Attorneys

• 

  David K. Colapinto

  Supervising Attorney

  Leading whistleblower attorney and expert across all practice areas.

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• 

  Stephen M. Kohn

  Chief Supervising Attorney

  Stephen M. Kohn is one of the nation’s leading whistleblower attorneys.

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• 

  Todd Yoder

  Supervising Attorney

  Represents whistleblowers in both federal litigation and whistleblower reward programs.

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Our International Tax Evasion Cases

Historic $104 Million Whistleblower Reward

Kohn, Kohn & Colapinto represented UBS whistleblower Bradley Birkenfeld in his historic tax whistleblowing case. A former international banker and wealth manager with UBS, Birkenfeld blew the whistle on a massive tax evasion scheme that helped U.S. citizens create secret Swiss offshore accounts to avoid U.S taxation. His disclosures resulted in the upending of the Swiss banking system. Birkenfeld received a record $104 million whistleblower award.

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“The only lawyer on my side was Steve Kohn. He was as smart as they come and feisty as a pit bull. Steve was convinced the government owed me a fat reward, and he was going to get it, or die trying.”

Bradley Birkenfeld

IRS Tax Whistleblower

$112.6 Million Award — Confidential Whistleblower

This anonymous whistleblower’s information [NH1] led authorities to identify 461 individuals engaged in tax fraud, resulting in over $562.9 million in collected fines and penalties. The whistleblower received awards exceeding $112.6 million, with additional sanctions and payouts anticipated as related enforcement actions continue.

$11.9 Million Award — Tax Case No. 2015-11701

Our client received an $11.9 million award in July 2023 through the IRS Whistleblower Program. The case, designated 2015-11701, resulted from information that enabled the IRS to collect substantial unpaid taxes.

$98 Million Award — Anonymous Offshore Whistleblower

An anonymous informant revealed sophisticated international tax evasion schemes involving offshore banking institutions. The resulting investigation caught 387 American taxpayers concealing millions in undisclosed foreign accounts, leading to a $98 million whistleblower award.

$100 Million Exposed — Alex “Sasha” Chepurko

At just 21 years old, Chepurko exposed a $100 million criminal operation and secured a $69.6 million judgment against the perpetrators. His case made legal history as the first to successfully leverage three major whistleblower statutes simultaneously: the False Claims Act, the Dodd-Frank Act, and the IRS whistleblower laws.

$17.4 Million Award — Tax Whistleblowers 21276-13W & 21277-13W

A married couple worked undercover in a confidential sting operation targeting an international criminal network that controlled more than $1.2 billion in hidden offshore accounts. Their courageous participation earned them a combined $17.4 million whistleblower award.

$135 Million Award — Anonymous DOJ & IRS Case

To safeguard our client’s identity, specific case details remain undisclosed. This substantial award underscores our firm’s commitment to maximizing recoveries for whistleblowers while protecting their confidentiality throughout the process.

IRS Whistleblower Awards Obtained

The total of all awards we’ve helped whistleblowers obtain is $424.52 million, making us the leading firm for tax evasion insiders. Given strict confidentiality of the IRS program, many of the names have been kept confidential.

Year	Name	Award Amount
2012	Bradley Birkenfeld	$104 Million
2015	Confidential Tax Whistleblower	$11.631 Million
2016	Confidential Tax Whistleblower	$17.79 Million
2017	Confidential Tax Whistleblower	$2.394 Million
2018	Confidential Tax Whistleblower	$145 Million
2018	Confidential Tax Whistleblower	$12.781 Million
2018	Confidential Tax Whistleblower	$24.473 Million
2019	Confidential Tax Whistleblower	$10.836 Million
2020	Confidential Tax Whistleblower	$5.284 Million
2020	Confidential Tax Whistleblowers	$6.7 Million
2020	Confidential Tax Whistleblower	$1.8 Million
2021	Confidential Tax Whistleblower	$5.3 Million
2022	Confidential Tax Whistleblower	$1.2 Million
2022	Confidential Tax Whistleblower	$15.911 Million
2023	Confidential Tax Whistleblower	$15.1 Million
2023	Confidential Tax Whistleblower	$11.9 Million
2024	Confidential Tax Whistleblower	$12.22 Million
2025	Confidential Tax Whistleblower	$20.2 Million

If you have information of tax evasion, there’s no better team to help guide you through the process of whistleblowing than the attorneys at IWA. Contact our tax team for a free and confidential consultation with one of our leading lawyers.

IRS Whistleblower Program: Brief Overview

About the IRS Whistleblower Office

Established through the Tax Relief and Health Care Act of 2006, the IRS Whistleblower Office compensates individuals who submit specific, credible information about tax non-compliance—including evasion, fraud, and other violations of internal revenue laws.

Whistleblower Awards

The IRS provides ranging from 15% to 30% of total government recoveries, encompassing taxes, penalties, and interest. In fiscal year 2024 alone, the IRS distributed $123.5 million in awards stemming from $474.7 million collected through whistleblower-provided information.

Eligibility Requirements

Qualifying for an award requires meeting several criteria. Whistleblowers must present solid, substantiated evidence of tax underpayment or violations — the IRS seeks concrete information rather than speculation or educated guesses. The anticipated government recovery must exceed $2 million, which may be aggregated across multiple tax years.

For cases involving individuals, the taxpayer’s annual gross income must surpass $200,000. Notably, U.S. citizenship is not required, and multiple individuals may file jointly, with awards apportioned based on each person’s contribution to the investigation.

Awards are not issued until the IRS has fully collected all taxes, penalties, and interest owed, and until the taxpayer has exhausted administrative and judicial appeals — a process that often spans several years.

Whistleblowers may also qualify for reduced awards when their information derives from public sources, depending on how significantly it advances the investigation.

Confidentiality

While truly anonymous submissions are not accepted, the IRS maintains strict confidentiality protections. Whistleblower identities remain private throughout the investigation and are only disclosed when necessary to finalize an award after case resolution.

Retaliation Protections

Whistleblowers who are identified and face employer retaliation for reporting tax non-compliance are entitled to legal protections under federal law.

Process to Report Tax Evasion to the IRS

How the Process Works

The IRS Whistleblower Office administers the program and evaluates all submissions. Given the strict procedural requirements involved, we strongly recommend working with an experienced IRS whistleblower attorney when reporting tax non-compliance.

The process begins when you complete and submit IRS Form 211 (Application for Award for Original Information), which goes directly to the IRS. After submission, your claim enters a queue for review. Communication from the IRS is typically limited during this period—you may only hear from them if an interview is needed or to receive a status update.

Once the case concludes, you’ll be notified of the outcome, whether an award is payable, and the amount. If you’re represented by counsel, your attorney will also receive notice.

This overview simplifies what is a complex process. Proper filing requires careful legal guidance to position whistleblowers for the maximum possible award. We encourage you to contact our IRS whistleblower lawyers for a free consultation to assess your eligibility.

Factors That Increase Awards

The strength and specificity of your evidence matter significantly — detailed financial records and witness accounts carry more weight, as does information not readily available through public sources. Cases involving substantial tax recoveries, complex schemes, or high-net-worth individuals tend to yield higher percentages.

The IRS also considers how directly your information contributed to their enforcement action and whether early reporting allowed them to intervene more effectively.

Factors That Reduce Awards

Award percentages decrease when information was already publicly accessible or known to the IRS. If the whistleblower participated in the underlying tax violation, awards may be substantially reduced or denied entirely. Delayed reporting that hampers the investigation can also negatively impact the final percentage.

Statute of Limitations

Reporting deadlines vary by violation type: three years for general underpayment, six years when gross income is understated by more than 25%, and no limit for fraud or unfiled returns. However, whistleblowers should act promptly — the IRS prefers cases with sufficient time remaining to complete a full investigation.

Get Help: Contact Us Today

Tax evasion cases demand experienced legal counsel — especially when significant dollars and awards are at stake. A whistleblower attorney evaluates your evidence, protects your identity, shields you from retaliation, and works to maximize your award by building a strong case and meeting crucial deadlines. They also serve as your liaison with the IRS throughout the process.

Get a Free and Confidential Consultation

If you’re considering coming forward, contact International Whistleblower Advocates for a free, confidential consultation.

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