An IRS cryptocurrency audit is no longer a theoretical concern for active traders, NFT participants, DeFi users, or anyone who has held digital assets through one of the bull cycles of the past decade. It is an active risk. And the agents conducting these examinations are increasingly trained, equipped, and supported by the agency’s data resources to develop adjustments that can carry into six and seven figures of assessed tax, penalties, and interest.

This article explains what an IRS cryptocurrency audit actually looks like from the inside — how returns are selected, what agents are trained to examine, what data the IRS already has, and where defense actually matters. The perspective is informed by Kugelman Law attorney Otto Bosch, a former Revenue Agent in the IRS Global High Wealth Group within the Large Business and International (LB&I) Division, paired with founder Alex Kugelman‘s nearly two decades of federal tax controversy experience and one of the country’s earliest dedicated cryptocurrency tax practices.

How the IRS Is Building Its Crypto Enforcement Capability

Understanding an IRS cryptocurrency audit starts with understanding what the IRS now knows — and how it knows it.

Exchange data through John Doe summonses. The IRS has used John Doe summonses to compel major U.S. cryptocurrency exchanges to produce account holder data, including identification information and transaction histories. The summonses served on Coinbase, Kraken, Circle, and others have produced datasets covering significant numbers of U.S. taxpayers. That data sits in IRS systems and is matched against filed returns.

Form 1099 reporting and digital asset broker rules. Expanded broker reporting rules require digital asset platforms to report transaction information directly to the IRS on information returns. The result is a steadily improving stream of third-party data that the IRS uses to identify reporting gaps, in much the same way W-2s and traditional 1099s are used.

The Form 1040 digital asset question. Every Form 1040 filed since 2019 has required the taxpayer to answer a yes-or-no question about digital asset activity. Answering that question incorrectly — particularly answering “no” when the taxpayer had reportable activity — is a fact the IRS pays attention to. It can support penalty positions, including in some circumstances civil fraud.

Blockchain analytics partnerships. The IRS works with blockchain analytics firms — Chainalysis among them — to trace transactions across the public blockchain, link wallet addresses to identified taxpayers, and reconstruct activity that occurred outside reporting exchanges. The blockchain is public; identifying who controls a particular address is the harder part, and the analytics tools the IRS has access to are increasingly capable of doing it.

Operation Hidden Treasure and successor initiatives. Beginning with Operation Hidden Treasure, the IRS has run dedicated training and enforcement programs focused on cryptocurrency. Revenue Agents working these cases receive specialized training. Specialized criminal investigation resources within IRS-CI focus on digital assets. And large-case examinations within LB&I increasingly include cryptocurrency-specific issue identification.

The cumulative effect is that an IRS cryptocurrency audit in 2026 is not the same examination it was five years ago. Agents arrive with significantly more information than taxpayers tend to assume.

Who Gets Selected for an IRS Cryptocurrency Audit

Crypto returns reach Revenue Agents through several paths, and the path tells the defense team something about the IRS’s interest in the case. As a general matter — and consistent with how returns are selected for examination across the IRS, which is covered in more depth in our guide to what IRS Revenue Agents do — crypto cases tend to be selected through:

• Information matching mismatches. When exchange-reported data shows reportable activity that does not appear on the taxpayer’s return, the gap is flagged for review. This is one of the most common entry points for crypto examinations.
• The Form 1040 digital asset question. Returns answering “no” while exchange data shows otherwise are high priority. So are returns answering “yes” with implausibly small reported activity relative to known holdings.
• John Doe summons follow-up. Account data produced through John Doe summonses is reviewed against filed returns; significant unreported activity surfaces examination candidates.
• Project initiatives. The IRS has run and continues to run focused enforcement projects on specific crypto issues — high-volume traders, NFT activity, DeFi transactions, and offshore exchange usage among them.
• Related-return pickups. When one taxpayer’s audit surfaces crypto activity involving counterparties — peer-to-peer transactions, partnership distributions of digital assets, business payments in crypto — the related taxpayer’s return can be opened for examination.
• Whistleblower referrals. The IRS Whistleblower Program receives, and acts on, referrals involving crypto activity.

The path matters because it shapes the examination. A mismatch-driven case usually starts narrow and follows the data. A project-driven case is concentrated on the project’s target issue. A John Doe summons follow-up may already include significant data the agent has reviewed before contacting the taxpayer.

What Revenue Agents Are Trained to Look For in a Cryptocurrency Audit

An IRS cryptocurrency audit covers a defined set of issues that Revenue Agents are trained to develop. Knowing what those issues are — before the first Information Document Request lands — is one of the most important advantages a defense team can bring to the table.

Unreported Disposition Income

The most common issue is straightforward: dispositions that should have been reported as taxable events were not. Every sale, trade, and use of cryptocurrency to purchase goods or services is generally a taxable event, and the gain or loss is calculated against the asset’s basis. Crypto-to-crypto trades are taxable. Spending Bitcoin on a meal is taxable. Swapping ETH for an NFT is taxable. Many taxpayers — and even some preparers — have historically missed these dispositions, and reconstructing them is the heart of most crypto examinations.

Basis and Holding Period Reconstruction

Once dispositions are identified, the next question is basis. What did the taxpayer pay for the asset, when, and how is the cost allocated across multiple acquisitions? Crypto basis is uniquely difficult because it spans years, exchanges, wallets, and methods of acquisition. Agents trained on these cases know that taxpayer-prepared crypto records are often incomplete, that exchange CSV exports do not always reconcile cleanly, and that an undocumented basis position will be challenged. Holding periods — long-term versus short-term — drive significant differences in tax rate and are scrutinized.

Income From Mining, Staking, Airdrops, and Hard Forks

Income items that arise outside of dispositions are a separate audit category. Mining and staking rewards are generally taxable as ordinary income at fair market value when received, and they create a basis carried into any later disposition. Airdrops and hard forks have IRS guidance — including Revenue Ruling 2019-24 — that agents apply. These items are routinely under-reported, and they are routinely raised in cryptocurrency examinations.

NFT-Specific Issues

Non-fungible tokens introduce their own audit issues: characterization questions (collectible versus capital asset versus inventory), royalty income, gas fees, the treatment of mints, and platform-specific reporting peculiarities. Revenue Agents working NFT tax compliance matters are trained on the issues that NFT activity tends to produce — and they tend to produce a lot of them.

DeFi Activity and Wrapped Tokens

DeFi protocols — lending, liquidity provision, yield farming, wrapping and unwrapping tokens — generate transactions that may or may not be taxable events depending on facts and characterization, and the area is technically nuanced. Agents look for the obvious — unreported income from yield farming and lending — and increasingly for the more sophisticated — characterization of liquidity pool entries and exits, and the tax consequences of wrapping transactions.

Foreign Exchange Use and FBAR Exposure

Use of foreign-domiciled cryptocurrency exchanges raises issues that go beyond the tax return itself. Foreign accounts holding cryptocurrency may trigger FBAR (FinCEN Form 114) and Form 8938 reporting obligations, and the IRS’s position on these obligations has evolved. Penalties for non-filing of FBARs and information returns can be severe and are independent of any income tax owed. Resolution typically involves streamlined offshore procedures, delinquent FBAR submissions, or other voluntary disclosure pathways depending on the facts.

The Form 1040 Digital Asset Question

Agents are specifically trained to examine the digital asset question on Form 1040. A “no” answer in a year of significant activity is a finding agents log and use — supporting accuracy-related penalties, in appropriate cases supporting fraud penalties, and in the most serious cases supporting referrals to IRS Criminal Investigation.

Pig Butchering and Investment Scam Losses

A growing area of crypto audit activity involves taxpayers who lost significant funds to pig butchering and similar crypto investment scams. The tax treatment of these losses is technical, the documentation challenges are significant, and the available deductions are narrower than many taxpayers and preparers assume. Audits in this area frequently turn on whether the taxpayer can substantiate the loss and characterize it correctly.

The Anatomy of an IRS Cryptocurrency Audit

Once an examination opens, a cryptocurrency audit follows the general arc of any IRS examination — but with crypto-specific document requests and analytical steps layered in. The early stages are often the most consequential.

The opening Information Document Request typically asks for, among other things: a complete list of every exchange and wallet ever used; CSV exports or transaction histories from each exchange; lists of self-custody wallet addresses and their public keys or transaction logs; mining and staking records; any tax software output (such as files from CoinTracker, Koinly, ZenLedger, or similar) used to prepare the return; and any third-party reports received. The first IDR is broad by design. It is the agent’s tool for understanding the universe of activity before drilling into specific issues.

How that first IDR is responded to often determines how the audit proceeds. Volunteering wallets the IRS does not appear to know about, providing reconciliations that reveal previously undisclosed activity, or producing records that contradict the return are decisions that should never be made without strategic review. They cannot be unmade later.

From there, the agent reconciles taxpayer-produced data against exchange records the IRS has received independently, runs blockchain analytics where appropriate, and develops issues. Specialists may be brought in for technical questions. The case proceeds through the same internal review and managerial sign-off architecture that governs any IRS examination, and closes with either a no-change, an agreed adjustment, or a Revenue Agent’s Report and 30-day letter setting up Appeals.

Why Crypto Audits Are Especially High-Stakes

An IRS cryptocurrency audit can quickly produce assessment exposure that surprises taxpayers. Several factors compound:

• Multi-year scope. Crypto audits frequently look at multiple years simultaneously. The statute of limitations is generally three years, but it extends to six years for substantial omissions and is unlimited for fraud or non-filed returns.
• Penalty stacking. Accuracy-related penalties (typically 20%) can be combined with FBAR penalties (which can reach the greater of $10,000 or 50% of account value per willful violation), Form 8938 penalties, and in serious cases civil fraud penalties (75%).
• Basis disputes that move large numbers. An undocumented basis position can convert what the taxpayer considered a modest gain into a much larger one. Where the taxpayer assumed $100,000 in basis and cannot prove it, the agent may treat basis as $0 — and the assessment moves accordingly.
• Foreign account exposure. Use of offshore exchanges or foreign-held wallets can trigger reporting obligations entirely separate from the income tax — with their own penalty regimes that can dwarf the underlying tax.
• Eggshell and reverse-eggshell concerns. Where significant activity was unreported and the digital asset question was answered “no,” civil examinations carry the possibility of referral to IRS-CI. Reading that risk correctly is critical.

This combination of factors is why a former IRS revenue agent attorney on the defense team is particularly valuable in cryptocurrency examinations. The technical issues are unfamiliar to most general tax practitioners. The risks compound quickly. And the IRS’s training, tooling, and posture in this space continue to evolve in ways most taxpayers cannot see from the outside.

How Kugelman Law Defends IRS Cryptocurrency Audits

Kugelman Law has defended cryptocurrency tax matters since the practice area existed. Alex Kugelman has been featured nationally on the Bitcoin.tax podcast and The Mark Milton Show discussing IRS digital asset enforcement, and he has built one of the country’s earliest dedicated cryptocurrency accounting and IRS crypto audit defense practices. Otto Bosch brings the inside-the-IRS perspective developed during his time as a Revenue Agent in the Global High Wealth Group within LB&I.

The combination matters in a crypto audit. Crypto fluency without IRS-insider perspective leaves the defense reading blind on the agent’s posture and the agency’s internal calculus. IRS-insider perspective without crypto fluency leaves the defense unable to engage the technical issues that drive the case. Both are necessary. Few firms offer both under one roof.

Representative outcomes from the firm’s controversy practice include a $365,000 tax debt reduced to a zero-dollar liability, a multi-year audit and non-filing matter resolved with minimal payment, and ten years of unfiled returns brought into compliance with a successful outcome. Results depend on specific facts. Past results do not guarantee future outcomes.

Frequently Asked Questions

Can the IRS see my crypto wallet?

The blockchain is public. Anyone can see transactions associated with a wallet address. What is not always public is who controls a particular address. The IRS uses blockchain analytics tools, exchange data obtained through John Doe summonses, expanded information reporting, and other techniques to associate addresses with identified taxpayers. Self-custody wallets are not invisible to the IRS — and the assumption that they are has produced significant exposure for taxpayers who relied on it.

What triggers an IRS cryptocurrency audit?

Common triggers include mismatches between exchange-reported data and the filed return, a “no” answer to the Form 1040 digital asset question paired with known activity, John Doe summons data, project-based enforcement initiatives, related-return pickups from another taxpayer’s audit, and whistleblower referrals. Selection paths shape the scope of the resulting examination.

Do I have to report crypto-to-crypto trades?

Yes. Under current IRS guidance, exchanges of one cryptocurrency for another are taxable events that produce gain or loss measured against the disposed asset’s basis. This is true even when no fiat currency is involved. Failure to report crypto-to-crypto trades is one of the most common issues identified in IRS cryptocurrency audits.

What if I used a foreign cryptocurrency exchange?

Use of foreign-domiciled exchanges can trigger FBAR and Form 8938 reporting obligations separate from the income tax return. Penalties for non-filing of these information returns can be severe. Resolution typically involves streamlined offshore procedures, delinquent FBAR submissions, or other voluntary disclosure programs depending on the specific facts and the willfulness analysis.

Can I just amend my returns to fix unreported crypto?

Sometimes — but the answer depends heavily on the facts. Amending returns can be the right approach in some cases and exactly the wrong approach in others, particularly where there is potential criminal exposure or where the taxpayer is already under examination. Decisions about amending, voluntarily disclosing, or simply waiting should be made with experienced controversy counsel — not unilaterally by the taxpayer or a preparer without controversy expertise.

Speak With Kugelman Law

If you are facing an IRS cryptocurrency audit, have received an IRS notice involving digital assets, or have unreported crypto activity you are trying to resolve correctly, schedule a paid privileged consultation with Kugelman Law. Call (415) 968-1780 or visit our contact page. All consultations are fully protected by attorney-client privilege.

At Kugelman Law, cryptocurrency tax controversy is a core practice area. Founder Alex Kugelman has been featured on the Bitcoin.tax podcast and The Mark Milton Show, and has represented clients in crypto audits, John Doe summons follow-ups, voluntary disclosures, and Tax Court litigation involving virtual currency. This guide explains the differences among the three letters, the risks of ignoring them, and how to respond effectively.

Why You Received an IRS Crypto Letter

The IRS initially issued Letters 6173, 6174, and 6174-A in 2019 to roughly 10,000 taxpayers identified through cryptocurrency exchange records. The program expanded substantially in subsequent years, and additional waves — including the more recent Letter 6371 — continue to be sent following new summons enforcement, routine 1099-B and 1099-DA matching, and data obtained through the Operation Hidden Treasure initiative.

In every case, the common denominator is the same: the IRS has matched your taxpayer identification number to cryptocurrency transaction activity that either does not appear on your return, appears in a manner inconsistent with third-party reporting, or raises compliance questions the agency wants resolved voluntarily.

Letter 6174: The “Soft” Notice

Letter 6174 is the least severe of the three. It is an educational notice — sometimes called the “no response needed” letter. The IRS is telling you it has information suggesting crypto activity and reminding you of your obligations to report virtual currency transactions. You are not required to respond.

That said, “not required” and “should ignore” are different things. If you received Letter 6174 and your returns did not accurately report crypto gains, losses, or income, the letter is a warning that the agency is watching. Correcting the issue through an amended return is far cheaper than waiting for a CP2000, an audit, or a criminal referral.

Letter 6174-A: The Escalated Soft Notice

Letter 6174-A resembles Letter 6174 but uses firmer language. It informs you that the IRS believes you may not have reported your crypto activity correctly and that you should review your returns and file amended returns if necessary. No response is technically required — but the IRS has flagged you at a higher confidence level, and the letter preserves the agency’s record that you were put on notice.

Receiving Letter 6174-A materially raises the stakes. If a subsequent examination determines that you underreported and the IRS can show you ignored 6174-A, the willfulness analysis — which drives the difference between a 20% accuracy-related penalty and a 75% civil fraud penalty — shifts dramatically against you. Reasonable cause defenses become harder to sustain when the agency can prove you were warned.

Letter 6173: The Response-Required Notice

Letter 6173 is fundamentally different. Unlike 6174 and 6174-A, it requires a response. The letter directs you to do one of three things by the stated deadline:

1. Certify under penalty of perjury that you properly reported all crypto transactions and owe no additional tax
2. File amended returns correcting any underreporting and pay the associated tax, interest, and penalties
3. Provide a detailed explanation of why you believe you are in compliance

The response is signed under penalty of perjury. That phrase matters. A false certification exposes you to penalties under 26 U.S.C. § 7206 — a felony carrying up to three years in prison and substantial fines. Signing a Letter 6173 response without a thorough pre-response review is among the riskier things a taxpayer can do in the tax controversy landscape.

Consequences of Ignoring Letter 6173

Failure to respond to Letter 6173 virtually guarantees an examination. The letter is not a random educational mailing — it is an enforcement tool, and the IRS has allocated examination resources specifically to pursue non-responders. Audits that follow ignored 6173 letters have elevated referral rates to IRS Criminal Investigation (CI), particularly where the transaction volume is significant.

What the IRS Already Knows About Your Crypto

By the time you receive any of these letters, the IRS has typically obtained your exchange records through one or more of the following channels:

• John Doe summonses served on Coinbase (2016), Kraken (2021), Circle/Poloniex (2021), SFOX (2022), M.Y. Safra Bank (2022), and various other exchanges
• 1099-B, 1099-MISC, 1099-K, and 1099-DA reporting from U.S. and U.S.-serving exchanges
• Cross-matching against Operation Hidden Treasure data
• Blockchain analytics performed by contractors such as Chainalysis and CipherTrace
• Information exchanges with foreign tax authorities under tax treaty and CRS frameworks

The exchange data the IRS receives typically includes gross proceeds from sales and dispositions, but frequently not cost basis. This asymmetry is what makes crypto tax audits expensive to defend: the IRS computer presumes zero basis, generating inflated proposed assessments. Reconstructing accurate basis across multiple exchanges, wallets, DeFi protocols, and chain bridges is technical work that benefits substantially from counsel and experienced forensic crypto accounting — a service we provide through our cryptocurrency accounting and audits practice.

How to Respond to an IRS Crypto Letter

Step One: Do Not Certify Without a Full Review

For Letter 6173 specifically, the temptation to sign a quick certification that everything was reported correctly is exactly the wrong move. Before certifying anything under penalty of perjury, every transaction must be reconstructed and reconciled against what was actually reported on the relevant year’s return.

Step Two: Reconstruct Your Transaction History

This requires pulling API-level data from every exchange, wallet, and DeFi protocol you used, mapping cost basis through transfers, identifying taxable events (including swaps, staking rewards, airdrops, hard forks, liquidity provision, lending, and NFT transactions), and applying a consistent accounting method. The output is a reconciliation that can be compared, line by line, against the returns as filed.

Step Three: Quantify the Exposure

Once the reconstruction is complete, you will know whether there was underreporting, and by how much. That figure — combined with penalty exposure and statute-of-limitations analysis — drives the response strategy.

Step Four: Choose the Right Path

Depending on the facts, appropriate paths may include:

• Filing amended returns and paying the tax, interest, and a potentially abatable penalty
• Submitting a formal response to Letter 6173 explaining compliance with supporting documentation
• Pursuing a Voluntary Disclosure Practice submission if the conduct involved willful underreporting
• For taxpayers with foreign exchange exposure, coordinating with Streamlined Offshore Procedures or Delinquent FBAR Procedures where applicable

Foreign Exchanges, FBAR, and Form 8938

If you held cryptocurrency on foreign exchanges — Binance (non-U.S.), Bitstamp, Bitfinex, KuCoin, OKX, or others — you likely have additional reporting obligations beyond income tax. FBAR filings (FinCEN Form 114) and Form 8938 filings under FATCA may apply, with penalty exposure that can be significantly higher than the underlying income tax liability. This is a frequent blind spot for U.S. crypto investors, and we address it directly through our offshore disclosure practice alongside our crypto work.

Criminal Exposure and Attorney-Client Privilege

Crypto cases sometimes carry criminal exposure — particularly where transaction volume is high, willful conduct is alleged, or funds were routed through mixers, tumblers, or privacy coins. An attorney-client privileged engagement is materially different from engaging a CPA or enrolled agent alone. CPA communications are not privileged in criminal matters under most circumstances; attorney communications are. If criminal exposure is a realistic concern, counsel should lead — and should engage any needed forensic accountants under a Kovel arrangement to extend privilege.

How Kugelman Law Handles IRS Crypto Letters

Our engagement begins with a paid, privileged consultation with Alex Kugelman. We review the letter, the relevant returns, and the exchange activity the IRS is likely relying on. We coordinate with our forensic crypto accounting partners to reconstruct transaction history where necessary, develop a response strategy calibrated to the specific letter and the client’s exposure, and handle all communications with the IRS. When audit or Tax Court work is required, we carry the matter through. Our firm has resolved crypto-related cases ranging from simple reconciliation errors to matters involving hundreds of thousands of transactions and seven-figure proposed assessments. Results depend on specific facts. Past results do not guarantee future outcomes.

Speak with a Cryptocurrency Tax Attorney

Kugelman Law offers paid, privileged consultations with founder Alex Kugelman — fully protected by attorney-client privilege. We do not offer free consultations. This is the same attorney-client privilege that protects you from having your communications discovered later in an audit or criminal matter.

Call (415) 968-1780 or schedule your consultation here. We represent cryptocurrency investors throughout California and nationwide.

Frequently Asked Questions About IRS Crypto Letters

Is Letter 6173 an audit?

Not yet. Letter 6173 is a response-required compliance notice. Ignoring it or submitting a false certification under penalty of perjury substantially increases the probability of a full examination — and in some cases, a criminal referral.

What’s the difference between Letter 6174 and Letter 6174-A?

Letter 6174 is educational and does not require a response. Letter 6174-A uses firmer language, reflects a higher IRS confidence level that you may have underreported, and materially strengthens the government’s willfulness case if noncompliance is later confirmed.

How much time do I have to respond to Letter 6173?

The letter states a specific deadline — typically 30 to 60 days from the date on the notice. That deadline can sometimes be extended by written request, but the extension should be negotiated by counsel rather than assumed.

Can I amend my returns instead of responding to Letter 6173?

Amending returns is one of the permitted responses and is frequently the right path. The amendments should be prepared carefully, pay tax plus interest and accuracy-related penalty exposure, and be accompanied by an appropriate response letter. Our firm regularly handles this process end to end.

What if the crypto activity was years ago and I didn’t know it was taxable?

Lack of knowledge does not eliminate the tax liability, but it can support reasonable cause defenses against penalties. The critical question is whether returns should be amended and what the penalty exposure looks like once the numbers are computed. Our unfiled and amended return practice addresses these scenarios routinely.

Will the IRS share my response with state tax authorities like the FTB?

Yes. The IRS and California Franchise Tax Board regularly share information, and federal amendments generally trigger state amendments. California residents should expect FTB follow-up on any federal crypto adjustment.

Do I need an attorney or can a CPA handle this?

A CPA can handle the reconciliation work. What a CPA cannot provide is attorney-client privilege in a criminal matter. If there is any realistic possibility of willfulness, fraud, or criminal exposure, counsel should lead and should engage forensic accounting under a Kovel arrangement to extend privilege. For smaller, clearly non-willful matters, a CPA may be sufficient — but the evaluation of which category you are in is itself something counsel is best suited to make.

Does Kugelman Law offer free consultations for crypto letters?

No. We offer paid, privileged consultations with Alex Kugelman. Because these matters can carry criminal exposure, privilege matters from the first conversation — and a free intake call is not privileged.

About the Author: Alex Kugelman

Alex Kugelman is the founder and managing attorney of Kugelman Law, a boutique tax controversy and cryptocurrency tax firm serving clients throughout California and nationwide. Admitted to the California Bar in 2008 (No. 255463) and the U.S. Supreme Court, Alex has nearly two decades of federal tax controversy experience, including litigation in U.S. Tax Court and U.S. District Court. He served as San Francisco Chair of the Federal Bar Association’s Tax Division in 2018 and is a member of the Marin County Assessment Appeals Board. He is a nationally recognized cryptocurrency tax authority, featured on the Bitcoin.tax podcast and The Mark Milton Show. J.D., Chapman University Fowler School of Law (2007); B.A., University of Colorado at Boulder (2001). Read Alex’s full bio.

Not all cryptocurrency audits are the same. Understanding the types of cryptocurrency tax audits the IRS conducts — and what typically triggers each — gives crypto investors, traders, miners, and businesses a meaningful head start in evaluating their exposure and their options.

A correspondence audit and a field audit may reach the same dollar figure in proposed adjustments, but they follow different procedural paths, demand different responses, and present different strategic opportunities.

Kugelman Law represents cryptocurrency taxpayers in IRS examinations nationwide. This guide explains the major categories of crypto audits, what tends to trigger each, and where the procedural differences actually matter.

The Three Primary Types of IRS Audits

At the federal level, the IRS conducts three main types of civil audits: correspondence audits, office audits, and field audits. Every cryptocurrency audit falls into one of these categories at the outset, though the IRS can escalate a matter from one type to another as it develops.

Understanding the distinction matters because it tells you what the examiner is likely to do, what records they are likely to demand, and how much scope the examination is likely to have.

Correspondence Audits

Correspondence audits are handled entirely by mail. They are the most common type of IRS audit overall and frequently the entry point for cryptocurrency examinations. A correspondence audit typically focuses on one or a small number of specific issues — often a mismatch between reporting the IRS received (for example, Form 1099-MISC, 1099-B, or the new Form 1099-DA for digital asset broker reporting) and what the taxpayer reported on their return.

For crypto investors, the classic correspondence audit arrives as a CP2000 notice. The IRS has received information from a centralized exchange reporting cryptocurrency transactions, compared it against the taxpayer’s return, and proposed adjustments for the difference. The notice identifies the proposed changes, computes the resulting tax and penalty exposure, and offers the taxpayer an opportunity to agree, disagree with explanation, or provide additional information.

Correspondence audits are narrower in scope than office or field audits, but they are not less serious. They can result in substantial liability, they can be escalated if the examiner is not satisfied with the response, and they create an administrative record that carries forward if the case proceeds to IRS Appeals or U.S. Tax Court litigation.

Office Audits

Office audits are conducted at an IRS office. The taxpayer (or their representative) is asked to appear in person, bringing specific records for examination. Office audits cover broader ground than correspondence audits and are typically used when the IRS has concerns that go beyond a single mismatch — for example, when multiple categories of income or deduction are in question, or when the initial inquiry expanded the examiner’s focus.

In crypto cases, office audits often arise when a correspondence audit escalates because the taxpayer’s response raised additional questions, or when the IRS’s internal review flags multiple concerns that cannot be resolved by mail. The in-person format gives the examiner an opportunity to ask follow-up questions in real time, which makes professional representation particularly important.

Field Audits

Field audits are the most comprehensive type of civil audit. They are typically conducted at the taxpayer’s home or place of business, or at the office of the taxpayer’s representative, and are assigned to revenue agents (rather than tax compliance officers, who handle correspondence and office audits). Revenue agents have broader authority and more specialized training, and field audits generally examine multiple tax years and multiple issues.

For cryptocurrency taxpayers, a field audit often signals that the IRS has identified a significant potential exposure — whether because of exchange reporting mismatches, blockchain analytics flags, offshore activity, high-dollar trading, mining or business-scale operations, or prior non-filing. Business entities engaged in crypto activity, including funds, mining operations, and crypto-focused businesses, are more likely to face field audits than retail investors.

The stakes in a field audit are almost always meaningful enough that experienced tax counsel is not optional. The IRS assigns its more capable examiners to these matters, and the procedural record created during the field examination carries directly into any subsequent Appeals or Tax Court proceeding.

Common Triggers of IRS Cryptocurrency Audits

The IRS has developed increasingly sophisticated tools for identifying cryptocurrency audit candidates. The agency combines exchange-level reporting, John Doe summons data, blockchain analytics (through contractors specializing in chain tracing), and traditional return-based analytics to flag returns for examination. The following are the most common triggers we see in the crypto audits we handle.

Exchange Reporting Mismatches

When a centralized exchange reports transactions to the IRS — whether on Form 1099-MISC, Form 1099-B, or the newer Form 1099-DA for digital asset broker reporting — and the taxpayer’s return does not reflect the reported activity, an automatic mismatch is flagged. This is the most common entry point for crypto correspondence audits.

John Doe Summons Data

The IRS has obtained transaction data from major U.S. exchanges through John Doe summonses — legal actions that compel an exchange to disclose information about unnamed account holders meeting specified criteria. Coinbase, Kraken, Poloniex, and Circle are among the exchanges that have been subject to such summonses. If your activity fell within the criteria of a summons, your account data is already in IRS hands, and any return inconsistency will be identified.

The Digital Asset Question on Form 1040

Since 2019, Form 1040 has asked a prominent question about digital asset activity. Answering “no” when the taxpayer had reportable activity — or leaving the question blank — is a recognized audit trigger. So is answering “yes” with a return that does not reflect digital asset transactions. The question is front-and-center on the return for a reason.

Large Unreported Gains

Substantial unexplained deposits, unreported capital gains relative to known activity, or lifestyle audits (where the IRS identifies spending inconsistent with reported income) all drive cryptocurrency examinations. High-dollar trading, especially during bull-market cycles, has produced examination waves in subsequent years.

DeFi, Staking, NFT, and Mining Activity

DeFi liquidity provision, staking rewards, airdrops, hard forks, NFT transactions, and mining income all have their own reporting rules, and many taxpayers either missed them or misreported them. The IRS has become increasingly focused on these areas. See our NFT accounting and tax compliance practice page for related coverage.

Foreign Exchange Use and Offshore Activity

Use of non-U.S. exchanges implicates FBAR (FinCEN Form 114) and Form 8938 reporting. Failure to file these forms can carry severe penalties independent of the underlying income tax issue, and a domestic crypto audit that reveals foreign exchange activity can quickly expand into an offshore compliance matter. Related procedural paths are discussed on our pages covering delinquent FBAR procedures, streamlined offshore procedures, and delinquent foreign information procedures.

Prior Non-Filing

Taxpayers with unfiled tax returns who also had crypto activity present a particularly acute exposure. The IRS can prepare substitutes for return on the taxpayer’s behalf, using adverse assumptions about cost basis and characterization. In matters we have handled, ten years of unfiled returns were resolved with a successful outcome. Results depend on specific facts. Past results do not guarantee future outcomes.

Criminal Investigations: A Separate Category

This article focuses on civil audits. Cryptocurrency matters can also attract criminal investigation, typically through the IRS Criminal Investigation Division (IRS-CI), when the facts suggest willfulness, evasion, or fraud. Indicators can include concealed wallets, false answers to the digital asset question, structured transactions designed to evade reporting, and use of mixers or privacy coins to obscure activity.

A civil audit that shows indicia of fraud can be referred for criminal investigation. If you have reason to believe your matter has criminal exposure — or if an IRS-CI special agent has contacted you — you should stop reading this article and call qualified tax counsel immediately. The procedural rules for criminal matters are materially different, and statements made during a civil audit can become evidence in a criminal proceeding.

State Tax Agency Audits

The IRS is not the only agency that audits cryptocurrency activity. State tax agencies — including the California Franchise Tax Board (FTB), the New York Department of Taxation and Finance, and comparable agencies in other states — conduct their own crypto audits. State audits can open independently of, or in parallel with, a federal examination, and they can reach different conclusions on the same facts because of differences in state law (including state conformity to federal characterization and state-specific penalty regimes).

State residency audits have also become a significant issue for high-income crypto taxpayers who moved out of high-tax states. A state may contest the timing or validity of a residency change, particularly if large crypto dispositions occurred around the move date.

Why the Type of Audit Changes Strategy

The type of audit you are facing meaningfully changes the right strategic response. Correspondence audits are paper fights — the focus is on producing targeted, well-framed documentation and closing the inquiry before scope expands.

Office audits introduce an in-person element where answers to off-script questions become part of the record. Field audits are comprehensive examinations where the IRS has committed resources because it expects to find something significant, and where early engagement of experienced counsel is essential.

Within each type, the crypto-specific wrinkles — cost basis reconstruction, DeFi and NFT characterization, foreign exchange issues, privilege considerations around CPA communications — layer on top of the standard procedural framework. The combination of audit type plus crypto complexity is what makes experienced tax counsel valuable.

What Happens Next: The Audit Process

Once an audit opens, it follows a predictable procedural sequence, regardless of type. The IRS issues Information Document Requests (IDRs) to obtain records. The examiner prepares an examination report. If agreement is not reached, the IRS issues a 30-day letter, then a 90-day letter (statutory notice of deficiency), after which the taxpayer’s only remaining path to contest the liability without first paying is a timely petition to U.S. Tax Court.

We cover this procedural arc in detail in our companion articles on the stages of an IRS cryptocurrency audit and responding to an IRS IDR in a crypto audit. For taxpayers already under examination, those procedural guides are the natural next reads.

In Our Experience

Crypto audits are not a theoretical concern. The IRS has committed significant resources to digital asset enforcement, and examination activity has grown materially every year. In matters we have handled, a $365,000 proposed tax debt was reduced to a zero-dollar liability, a multi-year audit and non-filing matter was resolved with minimal payment, and ten years of unfiled returns were resolved with a successful outcome. Results depend on specific facts. Past results do not guarantee future outcomes.

What those outcomes have in common is early engagement of experienced counsel, a disciplined procedural approach, and technical depth on the crypto-specific issues. Correspondence, office, and field audits all resolve more favorably when handled professionally from the start.

Nationwide Representation for Every Type of Crypto Audit

Federal cryptocurrency audits are federal matters, and Kugelman Law represents clients throughout the United States — all representation is provided remotely. Alex Kugelman is admitted to the U.S. Supreme Court and has nearly two decades of federal tax controversy experience, including U.S. Tax Court and U.S. District Court litigation. Our cryptocurrency specialization has been featured on the Bitcoin.tax podcast and The Mark Milton Show. Whatever type of crypto audit you are facing, we can represent you.

Frequently Asked Questions About Types of Cryptocurrency Audits

What are the different types of IRS cryptocurrency audits?

The IRS conducts three main types of audits: correspondence audits (handled by mail), office audits (at an IRS office), and field audits (at the taxpayer’s location or representative’s office). Crypto matters can involve any of the three, with higher-dollar or more complex cases typically escalating to office or field audits.

What triggers an IRS cryptocurrency audit?

Common triggers include mismatches between exchange reporting and reported income, data obtained through John Doe summonses against major exchanges, an inconsistent or missing answer to the digital asset question on Form 1040, large unreported gains, DeFi or NFT activity, and foreign exchange use implicating FBAR and offshore reporting.

Is a crypto correspondence audit less serious than a field audit?

Correspondence audits are generally narrower in scope than field audits, but they are not less serious. They can result in identical tax, interest, and penalty exposure, and they can be escalated or expanded if the examiner is not satisfied with the response.

Can a state tax agency audit my crypto separately from the IRS?

Yes. State tax agencies, including the California Franchise Tax Board, conduct their own crypto audits and can open examinations independently of or in parallel with an IRS audit. Federal and state audits can reach different conclusions on the same facts.

Does Kugelman Law represent clients in crypto audits nationwide?

Yes. Federal cryptocurrency audits are federal matters, and Kugelman Law represents clients throughout the United States. All representation is provided remotely.

Facing a Crypto Audit? Understand Your Options.

Whether you have received a CP2000 notice, an office audit letter, or a field audit opening, the right response depends on the type of audit and the facts of your case. Kugelman Law offers paid, privileged consultations with founder Alex Kugelman — fully protected by attorney-client privilege — to evaluate your exposure and your strategic options.

Call (415) 968-1780 or contact Kugelman Law to schedule your consultation.

About the Author

Alex Kugelman is the Founder and Managing Attorney of Kugelman Law, a boutique tax controversy and cryptocurrency tax law firm representing clients nationwide. He is admitted to the California Bar (2008, No. 255463) and the U.S. Supreme Court, and is a member of the American Bar Association, the California State Bar, and the Federal Bar Association, where he served as San Francisco Chair of the FBA Tax Division in 2018. Alex also serves on the Marin County Assessment Appeals Board. He holds a J.D. from Chapman University Fowler School of Law (2007) and a B.A. in English Literature from the University of Colorado at Boulder (2001).

With nearly two decades of federal tax controversy experience — including U.S. Tax Court and U.S. District Court litigation — Alex is nationally recognized for his cryptocurrency tax specialization and has been featured on the Bitcoin.tax podcast and The Mark Milton Show.

Related Kugelman Law Resources

• Cryptocurrency Accounting & Audits
• Tax Audits
• Tax Help
• Unfiled Tax Returns
• U.S. Tax Court Litigation
• NFT Accounting & Tax Compliance
• Delinquent FBAR Procedures
• Streamlined Offshore Procedures
• Delinquent Foreign Information Procedures

This article is for general informational purposes only and does not constitute legal advice. Reading this article does not create an attorney-client relationship with Kugelman Law. Results depend on specific facts. Past results do not guarantee future outcomes.