Letter 6173 is different: it generally requires a written response within about 30 days, and ignoring it can trigger an examination. But “no response required” is not the same as “nothing to do.”

The letter you received tells you how urgently the IRS is looking, not whether your returns are actually correct. That second question is the one that matters. Call (415) 968-1780 for a privileged consultation.

The IRS has sent several different cryptocurrency letters, and they are easy to mix up. The number in the corner of the page decides whether a deadline is running against you right now, so the first step is simply knowing which letter you are holding. This guide breaks down the differences and tells you what to do with each.

The quick comparison

Letter 6174: no response, but a real signal

Letter 6174 is the mildest of the three. It is educational, it alleges no specific error, and it requires nothing from you. If your crypto was reported accurately, you can file it away. T

he reason it still matters is that the IRS does not send these at random. It sends them because it received third-party information, usually from an exchange, tying you to digital-asset activity. If your reporting had gaps, the letter is a quiet, deadline-free chance to fix them before the IRS escalates.

Letter 6174-A: still no deadline, slightly sharper edge

Letter 6174-A looks almost identical to 6174 and also requires no response, but the wording carries a stronger hint that the IRS suspects your reporting may be incomplete, and it signals that follow-up action is possible. Treat 6174-A as a clearer nudge to review your prior returns than 6174. The absence of a deadline is an opportunity to get ahead of a problem, not a sign that one does not exist.

Letter 6173: this one has a clock

Letter 6173 is the serious one. Here the IRS is telling you it believes your returns are incomplete or incorrect, and it generally requires a written response within about 30 days. Your options usually include filing missing or amended returns, or submitting a statement, under penalties of perjury, explaining why you believe you already complied.

Ignoring a 6173 is itself a problem, because non-response can move the matter toward an examination. If you are holding a 6173, do not improvise. The response and its timing both carry weight, and this is the point to involve a tax attorney.

And a CP2000 is a different animal

If what you received is a CP2000 rather than a 6173 or 6174, you are a step further along. A CP2000 is not a soft letter; it is a proposed adjustment showing a calculated balance due because the IRS’s data did not match your return, and it carries a firm deadline. It is not a final bill, and the proposed numbers are often wrong or incomplete, but it must be answered on time and carefully.

The question that actually matters

Whichever letter you received, the deadline on the page is the smaller issue. The larger one is whether your past crypto reporting was complete and correct. A 6174 with accurate returns behind it may need no action at all. A 6174 sitting on top of years of unreported trades is a problem that will not improve with time, deadline or no deadline, because the IRS already has the underlying data.

The letter tells you how fast the IRS is moving. Your records tell you how exposed you are. Sort out the second question, ideally under attorney-client privilege, and the right response to the letter follows from it.

What to do next

Start by confirming which letter you have, then get your prior-year crypto position reviewed before you respond or amend. For the full picture of what Letter 6174 means and your options, see our hub guide, IRS Letter 6174 (crypto): what it means and what to do.

For how the firm defends matters that have already reached examination, see crypto tax audit defense and our cryptocurrency accounting and audits practice.

In one federal matter, two IRS Notices of Deficiency proposing more than $557,000 across six years were settled in U.S. Tax Court down to roughly $38,000, and with avoided interest and California exposure the client effectively saved over $1.2 million. Results depend on specific facts. Past results do not guarantee future outcomes.

Talk to a crypto tax attorney

If you are unsure which letter you received or what your exposure is, get a privileged assessment before you act. Schedule a paid, privileged consultation with Kugelman Law by calling (415) 968-1780 or visiting our contact page.

Frequently asked questions

Do I have to respond to IRS Letter 6174?

No. Letter 6174 does not require a response and carries no deadline. It is an educational letter telling you the IRS has information about your cryptocurrency activity. If your returns were accurate, no action may be needed; if they were not, you should address the gap even though nothing is formally due.

What is the difference between Letter 6174 and 6174-A?

Both are soft letters that require no response. The difference is tone: 6174-A more directly suggests the IRS believes your reporting may be incomplete and that it may follow up, while 6174 alleges no specific error. Treat 6174-A as the stronger warning.

Does Letter 6173 require a response?

Yes. Letter 6173 generally requires a written response within about 30 days, and non-response can trigger an examination. You may need to file missing or amended returns or submit a signed explanation. Because the response and its timing both matter, this is the point to involve a tax attorney.

What happens if I do nothing after a 6174 or 6174-A?

If your reporting was correct, likely nothing. If it was not, the issue does not disappear. The IRS already has the data, and the matter can escalate to a 6173, a CP2000, or an audit. Addressing a known gap early keeps the timing in your control.

Is a crypto letter the same as being audited?

No. None of these letters is an audit by itself. They are compliance and matching notices. They can, however, precede an examination if a real reporting problem exists and goes unaddressed.

About the author

Alex Kugelman is the founder and managing attorney of Kugelman Law and is nationally recognized for cryptocurrency tax. He has spoken on digital-asset tax and IRS enforcement on the Bitcoin.tax podcast and The Mark Milton Show. With nearly two decades of federal tax controversy experience, he is admitted in California and before the U.S. Supreme Court, the U.S. Tax Court, and the U.S. District Court for the Northern and Eastern Districts of California, and served as San Francisco Chair of the Federal Bar Association Tax Division in 2018. For matters that reach into IRS examinations, his colleague Otto Bosch, a former IRS Revenue Agent from the Global High Wealth group, leads the firm’s federal audit-defense work.

This article is attorney advertising and general information, not legal advice. Whether a given letter requires action, and which compliance path fits, are fact-specific legal determinations. Contacting Kugelman Law does not create an attorney-client relationship.