By Mike Ring | Blockchain Crypto Tax Prep
Your 1099-DA arrived. Your own records say something different. Congratulations — you’ve now discovered the defining experience of crypto tax season 2026.
This isn’t a glitch, and it isn’t necessarily your broker’s fault. It’s structural. The form was designed to capture what a custodial broker can see from inside its own walls. Everything outside those walls — self-custody, DeFi, cross-chain bridges, transfers between exchanges — doesn’t exist to them. You bought ETH on Coinbase in 2021, moved it to a hardware wallet, bridged it to Arbitrum, farmed some yield, bridged it back, and sold it on Kraken in 2025. Kraken’s 1099-DA sees a sale. It does not see a cost basis, a holding period, or any of the activity in between.
So yes, your 1099-DA doesn’t match your records. Here’s how to understand why, and what to do about it.
What Form 1099-DA Actually Is (And What It Isn’t)
Form 1099-DA — the “1099-Digital Asset” — is used by digital asset brokers to report certain transactions involving digital assets, such as cryptocurrencies and NFTs. It’s been required starting in 2026 for transactions occurring from January 1, 2025, and brokers operating in the United States must issue it with comprehensive details about qualifying transactions conducted on their platforms.
Digital asset brokers must file the forms with the IRS and send copies to the recipient investor, who then includes the details on their tax returns — specifically Form 1040, Schedule D, and Form 8949.
Here’s the critical nuance for the 2025 tax year: brokers are not required to report cost basis information — acquired value and acquisition date — on Forms 1099-DA for digital asset sale transactions in 2025. That means for most people filing right now, their 1099-DA is a gross proceeds document, not a gain/loss document. The actual tax result requires combining the reported proceeds with the taxpayer’s own records of purchase price, fees, and holding period to compute gain or loss. Taxpayers who simply plug in 1099-DA proceeds as “income” without reconciling basis are likely overstating taxable income, while those who ignore the forms altogether risk IRS mismatch notices.
The IRS has published a formal overview — Understanding your Form 1099-DA — which is worth bookmarking if you’re navigating this for the first time.
Why Your 1099-DA Doesn’t Match Your Records
This is the core question. There are five main reasons the numbers diverge, and most taxpayers hit at least two of them.
1. Transfers Are Invisible to Brokers
When you move crypto from one wallet or exchange to another, you’re not selling anything. No taxable event. But the receiving broker has no idea what you paid for those coins or when you bought them. Transferred-in and cross-exchange assets often have missing cost basis that must be reconstructed. The broker either reports “Unknown” in Box 1g or, in some cases, defaults to $0 — which is not the same as your actual cost basis.
The practical consequence: if you bought BTC elsewhere for $20,000, transferred it to an exchange, and sold it for $60,000, your 1099-DA may reflect $60,000 in proceeds and $0 in cost. That’s a $60,000 reported gain. Your actual gain is $40,000. You are responsible for correcting that.
2. Timing Differences
Brokers use transaction timestamps in UTC. Your own records — or the crypto tax software you used — may record trades in local time, or round to different precision. In a high-frequency year, even small timing discrepancies can cause transactions to fall in different tax years or misalign holding periods. Proper practice requires preserving original timestamps, normalizing to a consistent standard for reconciliation, and ensuring reported acquisition and disposition dates on the return align defensibly with broker-reported data.
3. Basis Method Conflicts
Under Revenue Procedure 2024-28, the IRS officially banned the “universal method” of pooling cost basis across different wallets. Effective January 1, 2025, you must track assets on a per-wallet or per-account basis — meaning you cannot use a high cost basis from a hardware wallet to offset a sale on a centralized exchange.
If your 2024 or earlier records were tracked using a universal/global average cost method, and your broker uses FIFO (first in, first out) — or vice versa — the basis figures won’t agree. This is especially common with long-time holders who’ve used multiple tracking tools over the years.
4. Missing Lots From Non-Covered Periods
Because cost basis reporting is not mandatory for assets acquired before 2026 (non-covered securities), taxpayers often need to reconcile their 1099-DA with their own records to ensure they do not overpay taxes on the full gross proceeds reported by the broker. Anything you bought before January 1, 2026 is non-covered for basis purposes — which is, for most active traders, essentially everything currently in their portfolio.
5. Transactions the 1099-DA Doesn’t Cover
Form 1099-DA only covers centralized exchanges. DeFi, staking, wrapping, lending, and on-chain activity are still taxable — and must be self-reported on Form 8949 or as ordinary income. The form may also exclude or aggregate certain transaction types: qualifying stablecoins below de minimis thresholds, specified NFTs under $600, and transactions deferred under Notice 2024-57 (wrapping, lending, staking). Your own comprehensive records will include all of those. Your 1099-DA won’t.
This creates a reverse gap: your records will show more activity than the 1099-DA. You still report it all.
The Three-Source Reconciliation
Before touching Form 8949, you need three data sources side by side:
Source 1 — Form 1099-DA: The IRS view of your proceeds from reportable broker-effected sales. Basis absent for most transactions in 2025. Source 2 — Exchange CSV or API: The broker’s full transaction record. This is where unreported basis most often hides. Source 3 — On-chain and wallet data: Ground truth for self-custody activity. Largely absent from the 1099-DA and must be self-reported.
The goal is not to match the form. It is to file an accurate return and document every discrepancy.
Here’s the workflow:
- Pull the full transaction CSV from every exchange you used in 2025. Not the PDF summary — the raw data file.
- Pull your on-chain history for every wallet address you controlled. Block explorers and your own wallet export tools are your primary sources here.
- Match 1099-DA line items to your records by date, asset, and proceeds amount. Flag any line where the proceeds differ by more than rounding.
- Identify missing basis. For every 1099-DA line where Box 1g says “Unknown,” find the original acquisition record in your own files.
- Check for transactions in your records that don’t appear on any 1099-DA — DeFi activity, self-custody sales, rewards — and add them to your tally.
- Document everything. Keep a master spreadsheet of every crypto purchase, transfer, and sale, including dates, amounts, fees, wallet addresses, and transaction hashes. This record is your proof if the IRS questions a cost basis adjustment.
Our pillar guide on 1099-DA missing cost basis covers the reconstruction process in deeper detail — including how to handle situations where original purchase records no longer exist.
Reporting the Reconciled Figures on Form 8949
Once you’ve done the work, Form 8949 is where it all lands.
Form 8949 allows you and the IRS to reconcile amounts that were reported to you and the IRS on Form 1099-B, Form 1099-DA, or Form 1099-S with the amounts you report on your return.
Form 8949 now features dedicated checkboxes (G through L) specifically for digital assets to distinguish them from traditional stocks. The box you check depends on whether basis was reported to the IRS:
- Box G / Box J: Short-term / long-term transactions where basis was reported to the IRS on the 1099-DA.
- Box H / Box K: Short-term / long-term transactions where basis was not reported to the IRS — the typical situation for 2025.
- Box I / Box L: Short-term / long-term transactions where you received no 1099-DA at all (self-custody sales, DeFi dispositions).
The mechanics for corrections:
- If you received a 1099-DA, always report the proceeds shown on the form in column (d) of Form 8949.
- If the form shows that basis was reported to the IRS, report that basis in column (e). If any correction or adjustment is needed, make it in column (g).
- Use column (f) to enter the relevant adjustment code. Code B applies when the cost basis reported on the form is incorrect and you’re substituting your own substantiated figure. Code E applies to disallowed wash sale losses.
- Attaching a brief reconciliation statement is not strictly required, but it can help if the IRS questions the discrepancy.
For the situation most traders are in — proceeds reported, basis unknown — the sequence is:
- Enter proceeds from the 1099-DA in column (d).
- Enter your reconstructed basis in column (e) from your own records.
- Check Box H (short-term) or Box K (long-term).
- Leave column (f) blank if no additional adjustment is needed; enter a code if there is one.
- Column (h) computes the gain or loss automatically.
Transactions that generated no 1099-DA — DeFi swaps, self-custody sales, DEX trades — go on separate rows under Box I or Box L, using your own records for both proceeds and basis.
The Enforcement Reality
It would be naive to treat this as a compliance formality.
Form 1099-DA delivers a partial ledger to the IRS, not a completed tax calculation. The enforcement system assumes taxpayers will supply the missing components. The form feeds into IRS information-return matching and analytics systems — systems that do not require cost basis to initiate review. Gross proceeds alone are sufficient to anchor wallet clustering, transaction tracing, and discrepancy analysis against Forms 8949, Schedule D, and historical filings.
CP2000 underreporting notices are generated based on mismatches between broker-reported proceeds and amounts reported or substantiated on the return — not on whether a broker supplied complete data.
Translation: “My broker didn’t give me a basis” is not a defense. The IRS will still generate a notice if your Schedule D proceeds don’t reconcile with what the broker filed. Your job is to file with the correct numbers — not the form’s numbers — and document why.
For a hands-on walkthrough of fixing missing basis before you file, see our 1099-DA missing cost basis solution page. And if you want to explore more crypto tax content and guides, the Insights hub has what you need.
FAQ
Q1: My 1099-DA shows way more proceeds than I actually made. Is that a mistake?
Not necessarily. The 1099-DA reports gross proceeds from every qualifying disposal — including trades where you swapped one crypto for another. If you sold $50,000 of BTC to buy ETH, then later sold that ETH for $30,000, the 1099-DA may show $80,000 in gross proceeds. That doesn’t mean you made $80,000 in profit. Gains and losses are calculated transaction by transaction against your cost basis — which is exactly why the reconciliation step exists.
Q2: The 1099-DA shows $0 or “Unknown” for my cost basis. What do I do?
You have the right to file your tax return with different numbers than what appears on your 1099-DA. The IRS expects this in some cases, particularly when cost basis is missing. Reconstruct your basis from original acquisition records — exchange purchase history, wallet imports, on-chain data — and enter your substantiated figure in column (e) of Form 8949. Keep every piece of documentation that supports the number.
Q3: I used multiple exchanges in 2025. Will I get a 1099-DA from each one?
Yes — each exchange issues its own 1099-DA. None can see what the others reported. You’ll need to reconcile each form separately against your records, then combine everything into a single Form 8949 (or as many pages as needed). Basis from Exchange A doesn’t carry over automatically to Exchange B, especially post-Rev. Proc. 2024-28.
Q4: Some brokers apparently have until February 2027 to issue 1099-DAs. What happens if mine arrives late?
The IRS has granted transition relief to certain brokers, meaning some may issue Forms 1099-DA up to one year late — i.e., February 2027. If a transaction wasn’t accounted for on your 2025 return and you receive a 1099-DA for it in 2027, you may need to file an amended return to reconcile the discrepancy. The more important point: receipt of a Form 1099-DA is not the triggering event for including an item on your return. If the transaction triggered income, gain, or loss, you should report it regardless.
Q5: What about DeFi activity, staking, or wrapped tokens — do they show up on the 1099-DA?
Generally no. Custodial exchanges report what happens on their platform. Everything else is your responsibility. Staking rewards are generally reportable as ordinary income when received (consult a tax professional on your specific situation — this area has seen ongoing guidance). DeFi swaps, LP entries and exits, and wrapping/unwrapping transactions are taxable events that you must track and self-report. None of this is news to anyone who’s actually done DeFi, but it’s worth saying clearly: the 1099-DA is not a complete picture of your taxable crypto activity.
Q6: I think my 1099-DA has errors. Should I contact the exchange?
Yes, as a first step. Contact the exchange first — some platforms have a process for issuing corrected 1099-DAs. If the exchange won’t issue a correction, or the timeline doesn’t work, you’re not stuck. Report the proceeds as shown on the form, enter your correct basis from your own records in column (e), and use the appropriate adjustment code in column (f). Document everything. The form isn’t the final word — your substantiated records are.
Q7: Do I need to attach my transaction records to my return?
Not automatically. Form 8949 itself is the disclosure mechanism. However, if you’re making basis adjustments that differ from what the broker reported, maintain a complete reconciliation file — your exchange CSVs, on-chain exports, timestamps, fee records — ready to produce if the IRS asks. An inquiry is possible; being able to respond with organized documentation is the difference between a resolved notice and a prolonged examination.
The Bottom Line
Your 1099-DA doesn’t match your records because it was never going to. It captures a slice of your activity — what one custodial broker could see — and does so with minimal basis data for the 2025 tax year. Your complete tax picture requires your own records, properly reconciled to the form, reported on Form 8949 with the correct basis and appropriate adjustment codes.
The IRS isn’t waiting for brokers to get their data perfect before it starts matching. Gross proceeds alone are enough to generate a CP2000 notice if your return doesn’t explain the gap.
Do the reconciliation. Document the discrepancies. File with the correct numbers — not just whatever the form says.
This post is for educational purposes only and does not constitute tax advice. Your situation may differ significantly depending on your transaction history, cost basis method elections, and applicable guidance. Consult a qualified tax professional before filing.
Need help with your crypto taxes? Mike Ring and the BCTP team handle the messy stuff — multi-chain DeFi, 1099-DAs that don’t add up, prior-year amendments. Free consult at cryptotaxprep.io or call 410-216-4632.
This isn’t tax advice. Talk to a professional about your specific situation.
