Say you bought $14,000 worth of Bitcoin, sold it for $15,000, and owed tax on the $1,000 profit. Simple enough. Now imagine the IRS received a form showing only the $15,000 sale, with no record of what you originally paid. To the agency’s automated systems, that entire $15,000 looks like taxable income. You could get a letter saying you owe thousands more than you actually do.
That scenario is not hypothetical. It is baked into the design of the IRS’s new crypto reporting form, and it could affect millions of digital asset investors starting with the current filing cycle.
What the 1099-DA actually reports
The form is called the 1099-DA, short for “Digital Asset Proceeds From Broker Transactions.” Under final rules the IRS published in 2024 as Treasury Decision 10000 (89 FR 56480), crypto brokers, including major exchanges and certain payment processors, must now file this form for covered sales.
But the rollout has a significant gap. Gross proceeds reporting kicked in for sales occurring after January 1, 2025. Cost basis reporting, the part that shows what you originally paid for the asset, does not apply until transactions occurring after January 1, 2026. For an entire year of trades, the IRS and taxpayers will receive statements showing what an asset sold for but not what it cost to acquire.
The missing number is not a minor detail. It is the only figure that separates a real capital gain from an inflated one.
Why the gap overstates what investors owe
The IRS uses information returns like the 1099 series to cross-check what taxpayers report on their own filings. Its Automated Underreporter (AUR) system compares third-party data against individual returns and flags discrepancies. When a 1099-DA arrives showing $15,000 in gross proceeds and a blank cost basis field, the AUR system has no purchase price to subtract. By default, it can treat the full amount as a potential gain.
This is not speculation about how the system might behave. It is how the AUR has historically handled analogous forms. When cost basis reporting for stocks and bonds was phased in between 2011 and 2012 under the Emergency Economic Stabilization Act of 2008, brokers filed 1099-B forms that similarly lacked basis for certain transactions. Taxpayers who reported accurate gains on their returns still received CP2000 notices, letters proposing additional tax, interest, and sometimes penalties, because the IRS matching system saw a gap between reported proceeds and reported income.
The same dynamic is now playing out with crypto. If your return reports $1,000 in profit from a Bitcoin sale but the 1099-DA shows $15,000 in proceeds with no basis, the system sees a $14,000 discrepancy. A CP2000 notice is not a bill or an audit, but it demands a response, and ignoring it can escalate into an actual assessment.
For investors who traded frequently across 2025, the numbers stack up fast. Someone who made dozens of trades totaling $200,000 in gross proceeds but only $8,000 in net gains could face a notice suggesting they failed to report six figures of income. The IRS is not claiming the taxpayer cheated. The system is simply working with incomplete data.
What the IRS has said, and what it has not
The Treasury Department framed the new regulations as a tool to improve tax compliance and reduce evasion in the digital asset space, according to its press release (JY2438). Regulators also signaled they knew the early data would be incomplete. Notice 2024-56, published in Internal Revenue Bulletin 2024-29, provides transitional penalty relief for brokers who make a good-faith effort to comply during the phase-in period.
That relief, however, is aimed at brokers, not individual taxpayers. Nothing in the published guidance indicates the IRS will build a filter into its AUR system to delay or suppress CP2000 notices generated by 1099-DA forms that lack cost basis. No IRS or Treasury document has disclosed how many forms are expected to arrive without basis data, though the number is likely large given that millions of Americans hold crypto on platforms like Coinbase, Kraken, and Gemini. A 2023 Pew Research Center survey found that roughly 17% of U.S. adults said they had invested in, traded, or used cryptocurrency.
As of June 2026, several practical questions remain open. The IRS has not said whether it will adjust its matching algorithms to account for the known absence of cost basis on early 1099-DA filings. Brokers still lack clear guidance on how to handle transfers between platforms, self-custody wallets, or decentralized protocols where acquisition history may not exist on the reporting broker’s system. And it is unclear whether popular tax preparation software, such as TurboTax or H&R Block, will automatically flag the discrepancy and prompt users to enter cost basis manually when importing 1099-DA data.
Tax professionals have been watching for additional IRS guidance, but no updated timeline or clarification has appeared in official channels since the original rulemaking.
What crypto investors should do now
The upshot for anyone who sold crypto in 2025: you cannot rely on the 1099-DA as a complete record of your tax position. The form will show what came in from a sale. It will not show what went out to buy the asset in the first place. Filling that gap is your responsibility.
Keep your own records. Download transaction histories from every exchange you used. If you moved assets between platforms or into self-custody wallets before selling, document the original purchase date, price, and any fees. Third-party portfolio trackers like CoinTracker, Koinly, and CoinLedger can help reconstruct cost basis across multiple wallets and exchanges, though they require accurate import data to work correctly.
File a return that tells the full story. When your return reports actual gains and losses with supporting documentation, it creates a record the IRS can compare against the incomplete 1099-DA. If a CP2000 notice arrives months later, that documentation is your primary defense. Responding with clear records showing your true cost basis can resolve the discrepancy without escalation.
Check your IRS transcripts early. You can review what the IRS has on file through the agency’s online account portal. Spotting a mismatch between reported proceeds and your filed return before a notice arrives gives you more time to prepare a response or file an amendment. High-volume traders and businesses should also monitor the business account portal for broker reports that look incomplete.
Talk to your broker. Even where cost basis is not required on the 1099-DA under the phased rules, some brokers may provide supplemental statements or data exports that include acquisition cost. Asking for that information now, rather than after a notice arrives, saves time and stress.
A compliance system running on half the data
The IRS designed the 1099-DA to bring crypto reporting in line with the standards that already apply to stocks and bonds. That goal is reasonable, and the long-term effect should be better compliance across the board. But the decision to phase in proceeds reporting a full year before cost basis reporting created a gap that was easy to foresee: for the duration, the agency’s own compliance systems will be working with half the picture.
Honest taxpayers who reported their gains accurately could still receive alarming letters suggesting they owe thousands, or tens of thousands, more than they do. The IRS may eventually refine its matching process or expand basis reporting to close the gap. Until then, the burden of proving you do not owe inflated taxes falls on the person who filed the return. The best protection is not a tax strategy. It is a spreadsheet.
