The taxpayer, by contrast, often has incomplete records, CSV exports that do not reconcile cleanly, transactions spread across exchanges that no longer exist, and no clear sense of how to characterize half of the activity on the return.

That asymmetry is what makes crypto tax audit defense different from most other audit defense work. It is also why an inside-the-IRS perspective — knowing what the agent is actually looking at, how they have been trained to develop the case, and where their analytical framework is strongest and weakest — is so consequential to the outcome.

This article explains how Kugelman Law approaches crypto audit defense, with the perspective of attorney Otto Bosch, who served as a Revenue Agent in the IRS Global High Wealth Group within the Large Business and International (LB&I) Division before joining the firm in February 2026, paired with founder Alex Kugelman‘s nationally recognized cryptocurrency tax practice.

For background on what the IRS is doing in this space, see our companion article on inside an IRS cryptocurrency audit.

The Defensive Challenge in a Crypto Audit

Crypto audits combine several characteristics that, in combination, make them uniquely difficult to defend without specialized methodology:

• Volume. Active crypto traders, NFT participants, and DeFi users can have thousands or tens of thousands of transactions across dozens of exchanges and wallets over multi-year periods. The volume alone produces complexity that ordinary audit defense workflows are not designed to handle.
• Recordkeeping gaps. Exchanges shut down. Hot wallets get rolled into cold storage. CSV exports lose detail. Pre-2017 records are often nonexistent. The defense routinely operates with incomplete data that the IRS does not have either — but the burden of substantiation is on the taxpayer.
• Characterization ambiguity. Was that DeFi transaction a taxable event or not? Is the wrapping of a token a disposition? How is a liquidity pool exit characterized? Many crypto issues do not have clear IRS guidance, and the agent and the taxpayer can be looking at the same transactions and reaching different conclusions.
• The IRS’s data advantage. Through John Doe summons data, blockchain analytics partnerships, and broker reporting, the IRS sometimes knows about specific transactions the taxpayer does not remember.
• The Form 1040 digital asset question. A “no” answer on the digital asset question, paired with significant exchange activity, is a finding the agent will use throughout the case — for penalty positions, for willfulness analysis, and (in serious cases) for criminal referral consideration.

Each of these challenges has a defensive response. Together, they require methodology — not improvisation.

Phase One: Pre-Response Case Analysis

The first thing a former IRS agent does on a crypto audit is read the case before doing anything else. That means understanding what the IRS likely knows, what the IRS likely does not know, what the audit’s selection path tells the defense about the agent’s working hypothesis, and what the worst-case scenario looks like if the case develops adversely.

Specifically, the pre-response analysis includes:

• What does the IRS already have? If the audit was triggered by exchange data from a John Doe summons, the IRS has the data. If it was triggered by a Form 1040 digital asset question mismatch, the IRS knows what triggered it. If it was triggered by a related-return pickup, the IRS knows the connection. Reading the selection path is one of the first defensive moves.
• What is the taxpayer’s actual exposure? This requires reconstructing the full activity universe — every exchange, every wallet, every transaction type — and modeling the tax outcome before responding to the first Information Document Request.
• Are there parallel issues? Crypto activity often comes paired with foreign account issues (FBAR, Form 8938), unreported income from mining or staking, NFT royalty income, or other items that may not yet be on the agent’s radar but could become so.
• Is there potential for criminal exposure? Where the digital asset question was answered “no” while material activity existed, where amounts are significant, or where the pattern suggests willfulness, the audit may be — or may become — an eggshell audit. We covered the eggshell defense framework in detail in our article on eggshell audits explained.

The output of this phase is a defensive baseline: a clear picture of the case from both sides of the table before a single document is produced.

Phase Two: Reconstruction and Substantiation

Most crypto audits ultimately turn on reconstruction. The defense’s job is to produce a defensible record of activity, basis, and income — and to do so in a way that the agent’s blockchain analytics tools will validate rather than contradict.

Key elements of the reconstruction work:

• Exchange data consolidation. Pulling CSV exports, transaction histories, and tax reports from every exchange the taxpayer used, then reconciling across them to identify overlaps, gaps, and inconsistencies.
• Self-custody wallet tracing. Identifying every self-custody wallet, public address, and on-chain transaction. Where wallets are linked through transfers, the defense’s reconstruction has to match what blockchain analytics will show.
• Basis methodology selection. FIFO, LIFO, specific identification, average cost — the choice of basis methodology has real tax consequences and has to be applied consistently. Where prior years used one methodology and the audit year uses another, the inconsistency becomes a defense issue.
• Income item reconstruction. Mining rewards, staking rewards, airdrops, hard forks, and DeFi income items each have specific rules and require contemporaneous fair market value determinations.
• NFT-specific reconstruction. Mint cost, gas fees, royalty income, and marketplace fees — NFT activity requires its own analytical layer.
• Foreign exchange identification. Activity on offshore exchanges triggers FBAR and Form 8938 considerations that must be developed in parallel with the income tax analysis.

The objective of the reconstruction is not to produce a document that satisfies the agent. The objective is to produce a record that withstands the agent’s verification, the appeals officer’s later review, and (if necessary) the U.S. Tax Court’s examination of the workpapers.

Phase Three: Document Strategy and IDR Response

Once the case has been read and the reconstruction is in hand, the defense engages with the IRS’s Information Document Requests. As we covered in detail in our article on how to respond to an IRS IDR, IDR responses are not paperwork exercises — they are deliberate, strategic communications that frame the audit’s record.

In crypto audits, the IDR response strategy involves several specific considerations:

• Scope clarification on broad requests. The opening IDR in a crypto audit is often written broadly. “All cryptocurrency transactions for tax years 20XX through 20XX” is the kind of request that can almost always be narrowed through respectful negotiation.
• Producing reconstructions rather than raw data. Where appropriate, providing the agent with a clean, reconciled summary of activity — with the underlying data available on request — produces a better record than dumping raw CSV files the agent has to interpret.
• Privilege review of advisor communications. Communications with tax preparers, accountants, and prior counsel about crypto positions may be privileged and should be reviewed before production.
• The disclosure analysis. Information about wallets or exchanges the IRS does not appear to know about is the single most consequential disclosure decision in any crypto audit. That decision should never be made without legal analysis.
• Reconciling with what the IRS likely already has. Where the defense’s reconstruction differs from what the IRS will see in its own data, those gaps need to be explained — not ignored.

Phase Four: Engaging With the Agent’s Blockchain Analytics

One of the more sophisticated aspects of crypto audit defense is engaging substantively with the blockchain analytics the IRS uses. Agents in crypto examinations are often working with output from tools like Chainalysis, and the analytics produces conclusions the defense will eventually need to address.

The defense’s role here includes:

• Understanding what the analytics actually shows and what it does not. Analytics tools attribute wallets to identified taxpayers with varying degrees of confidence. Some attributions are airtight. Others rest on inference. Knowing which is which matters.
• Identifying analytic errors. Misattributed wallets, transactions that the analytics counts twice, transfers between the taxpayer’s own wallets that should not be treated as dispositions — these are common analytic errors that can move large numbers.
• Producing counter-reconstructions. Where the defense’s reconstruction differs from the IRS’s analytics output, the difference needs to be explained with documentation.

Inside-the-IRS experience matters here. Agents have specific training on how to use these tools, and counsel who has been inside the IRS recognizes both the tools’ strengths and their characteristic failure modes.

Phase Five: Negotiating Crypto-Specific Positions

Crypto audits frequently involve issues where the law is unsettled, where IRS guidance is ambiguous, or where the agent’s position is technically defensible but practically negotiable. The defense’s job is to identify these positions early and to negotiate them on terms favorable to the taxpayer.

Common negotiation points in crypto audits include:

• Basis methodology disputes. Where the agent is treating undocumented basis as zero, the defense may be able to negotiate a reasonable basis position with appropriate substantiation.
• Characterization questions. Whether a particular transaction is a taxable disposition, a like-kind exchange (for pre-2018 trades), a borrowing rather than a sale, or something else — these characterization questions are often negotiable.
• Penalty mitigation. Accuracy-related penalties under Section 6662 are not automatic. Reasonable cause defenses, reliance on tax software output, reliance on professional advice, and other mitigating facts can reduce or eliminate penalty exposure.
• Willfulness defenses. Where FBAR issues are in play, the willfulness analysis drives penalty exposure significantly. A defensible non-willful posture can move outcomes by orders of magnitude.

Phase Six: The Escalation Path

Most crypto audits should be resolved at the examination level when possible. But the defense’s posture should always be calibrated to the possibility that the case escalates — to Appeals, to U.S. Tax Court, or, in the most serious matters, to a voluntary disclosure pathway.

The escalation analysis includes:

• Settlement leverage. What is the realistic best and worst case at the agent level versus at Appeals? Where Appeals would likely produce a better outcome, the defense’s posture at the examination level shifts.
• Litigation readiness. If the case proceeds to U.S. Tax Court, the record built during the examination is what the case is decided on. The defense’s IDR responses, written communications, and document production should be calibrated accordingly from day one.
• Voluntary disclosure as a parallel option. For the most serious cases involving significant unreported activity, false answers to the digital asset question, or undisclosed offshore exchange use, the IRS Voluntary Disclosure Practice may be the strategically correct path. The decision to pursue VDP is consequential and time-sensitive — generally available only before IRS discovery.

For foreign-exchange-related issues, streamlined offshore procedures, delinquent FBAR procedures, and delinquent foreign information return procedures provide alternative pathways depending on willfulness.

How Kugelman Law’s Combined Capability Shapes the Defense

Kugelman Law is structured deliberately for crypto controversy work. Alex Kugelman has been featured nationally on the Bitcoin.tax podcast and The Mark Milton Show discussing IRS digital asset enforcement, and has built one of the country’s earliest dedicated cryptocurrency tax practices through the firm’s cryptocurrency accounting and audits service. Otto Bosch brings the inside-the-IRS perspective from his time as a Revenue Agent in the LB&I Global High Wealth Group.

The combination is the point. Crypto fluency without IRS-insider perspective leaves the defense reading blind on the agent’s posture and the IRS’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 in the country offer both under one roof. For an extended discussion of how that combined capability shapes audit defense, see our article on why a former IRS revenue agent attorney changes audit defense.

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

What makes a crypto tax audit different from a regular tax audit?

Crypto tax audits involve transaction volumes, recordkeeping gaps, characterization ambiguities, and an asymmetric data environment that are uncommon in other types of audits. The IRS has built specific enforcement infrastructure for digital asset cases — including blockchain analytics, John Doe summons data, and dedicated training — and the defense methodology has to be calibrated accordingly.

Can I defend a crypto audit using my regular accountant?

For straightforward documentation-focused crypto matters, sometimes. For substantive crypto audits — particularly those involving significant amounts, multi-year activity, foreign exchange use, or any potential criminal exposure — attorney representation with crypto-specific experience is generally appropriate. The privilege protection, technical specialization, and litigation backstop matter in this space.

What is the most common issue in a crypto audit?

Unreported dispositions and undocumented basis are the two largest single issues in most crypto audits. Mining, staking, airdrop, and hard fork income items are also routinely under-reported. NFT-specific issues, DeFi characterization questions, and foreign exchange use round out the most common categories.

How does the IRS know about my crypto wallets?

The IRS has access to exchange data produced through John Doe summonses (Coinbase, Kraken, Circle, and others), expanded broker reporting under digital asset rules, blockchain analytics tools that trace transactions across wallet addresses, intergovernmental information exchange agreements for foreign-domiciled exchanges, and a growing array of other data sources. 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.

Should I amend my returns before the IRS opens an audit?

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. The decision should be made with experienced controversy counsel, not unilaterally.

Speak With Kugelman Law

If you are facing an IRS cryptocurrency audit, have received an IRS notice involving digital assets, or are weighing how to resolve crypto tax compliance issues before they reach an examination, 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.

About the Author

Alex Kugelman is the founder and managing attorney of Kugelman Law, a boutique tax controversy and cryptocurrency tax firm serving California and clients nationwide. With nearly two decades of federal tax controversy experience — including litigation in the U.S. Tax Court and U.S. District Court — Alex represents individuals and businesses in their most consequential disputes with the IRS and the California Franchise Tax Board. He is a member of the State Bar of California (No. 255463), admitted to the Bar of the U.S. Supreme Court, and served as San Francisco Chair of the Federal Bar Association’s Tax Division in 2018. He is also a member of the Marin County Assessment Appeals Board and a nationally recognized cryptocurrency tax attorney featured on the Bitcoin.tax podcast and The Mark Milton Show. Read Alex’s full bio.