10 Crypto Tax Mistakes That Trigger IRS Notices

Short answer: Most IRS crypto notices are CP2000 proposed adjustments caused by mismatched data, not audits. The biggest triggers: answering No to the Form 1040 digital asset question after selling, ignoring a Form 1099-DA that does not match your return, reporting only cash-outs while skipping crypto-to-crypto swaps, and losing cost basis for coins moved between exchanges. Complete records and a return reconciled to the forms the IRS already received prevent most of them.

Most crypto tax problems don’t start as audits. They start as a computer matching the forms it received against the return you filed – and finding a gap.

The 10 mistakes

1. Answering ‘No’ to the 1040 digital-asset question after selling.
2. Ignoring 1099-DA mismatches – the IRS computer matches them automatically.
3. Reporting only cash-outs and skipping crypto-to-crypto swaps.
4. Losing cost basis for coins moved between exchanges.
5. Forgetting staking/mining income (it’s income even if you never sold). See our staking, mining and airdrops guide.
6. Leaving a closed exchange or DeFi wallet out entirely.
7. Netting everything into one line instead of listing disposals on 8949. See our guide to reporting on Form 8949.
8. Missing FBAR/Form 8938 analysis for large foreign-exchange balances.
9. Filing in a new state without checking its rules.
10. Waiting for an IRS letter instead of amending (1040-X) when you find an error.

Why most notices are fixable

Most notices are CP2000 proposed adjustments, not audits – they arise from mismatched data, and they are usually fixable with records. The cheapest protection is boring: complete records, reconciled forms, and a return that matches what the IRS was already sent.

Frequently asked questions

What is a CP2000 notice?

A CP2000 is a proposed adjustment, not an audit: the IRS computer matched the forms it received (such as a Form 1099-DA) against your return and found a mismatch. It proposes additional tax, and you can agree or dispute it with records.

What if I made a mistake in a past year?

Don’t wait for an IRS letter: amend with Form 1040-X when you find an error.

Do I need FBAR for a foreign crypto exchange?

It depends on your foreign holdings. Large foreign-exchange balances may need FBAR or Form 8938 analysis – check the requirements before filing, and don’t skip the analysis.

Related guides

• Form 1099-DA Explained: The New Crypto Tax Form for 2025-2026
• How to Report Crypto on Your Taxes: Form 8949 & Schedule D, Step by Step
• How Crypto Is Taxed in the US: The Complete 2026 Beginner’s Guide

Sources

• IRS Digital Assets – IRS guidance hub for digital assets.
• IRS Form 1040-X – amended individual income tax return.
• FinCEN FBAR rules – report of foreign bank and financial accounts.

This guide is general education only – not tax, legal or financial advice. Verify with the source authority and a qualified tax professional before filing.