By Mike Ring
Your 1099-DA arrived. It says you have $340,000 in proceeds. Your bank account says $23,000. Both numbers are technically correct, and that’s the whole problem.
The 1099-DA is the IRS’s new crypto information return — brokers are required to report your proceeds from crypto sales. What they are not always required to report, especially in this first wave of forms, is your cost basis. When cost basis is missing or reported as zero, the implied gain on your 1099-DA is wildly overstated. You didn’t make $340,000. But the IRS’s copy of your form suggests you did.
This guide is for anyone staring at a 1099-DA number that looks like a typo. We’ll walk through why the figure is so often wrong, what causes it, how to verify your actual gain, and how to correct it properly on Form 8949 so you don’t hand the IRS money you don’t owe.
Why 1099-DA Numbers Are So Often Wrong
Let’s start with the most common culprit, because it explains the majority of panic we see during tax season.
Missing or Zero Cost Basis
Brokers report proceeds — what you received when you sold. That part they’ve generally got. What they often don’t have is your cost basis — what you originally paid, plus any fees, adjusted for splits, forks, or other events.
Why not? Because:
- You bought on a different exchange. If you bought ETH on Kraken in 2019 and transferred it to Coinbase before selling in 2024, Coinbase has no idea what you paid. They see a transfer in with no acquisition data attached.
- You self-custodied first. Bought on an exchange, moved to a hardware wallet, then moved back to sell. The original cost data rarely travels with the asset.
- The exchange doesn’t have historical records. Pre-2023 activity on many platforms wasn’t tracked with basis in mind. Some exchanges simply don’t have it.
- The asset is “noncovered.” Pre-2023 crypto acquisitions are generally considered “noncovered securities” — brokers aren’t legally required to report basis on them yet. So they don’t.
When basis is missing, a broker has two options: report $0, or leave it blank. Either way, the software calculating your tax liability treats it as a pure gain. $10,000 proceeds with $0 basis = $10,000 taxable gain. But if you paid $8,000 for that position, your actual gain is $1,000. The difference is your problem to fix, not theirs.
For a deeper look at this specific issue, our pillar guide on 1099-DA missing cost basis covers the mechanics in detail.
Other Reasons Your 1099-DA Is Overstated
Missing basis is the big one. But it’s not the only way your form ends up wrong.
Transfers Counted as Sales
Moving crypto between wallets you own — Coinbase to MetaMask, or exchange A to exchange B — is not a taxable event. It’s just moving your own property around. But some brokers, particularly those with incomplete wallet-linking logic, report transfers out as sales. If that transaction shows up on your 1099-DA as proceeds, your total is inflated by a transaction that never actually happened.
Wrong Basis Method Applied
The IRS allows several cost basis accounting methods: FIFO (first-in, first-out), specific identification, and others. Most brokers default to FIFO unless you instruct them otherwise. If you’ve been using a different method across your trading history, the broker’s FIFO calculation may assign the wrong lots to your sales — producing a larger gain than you’d have under the method you’ve actually been applying.
Duplicate Lots
This one’s subtle. If an asset was reported on both a Form 1099 from an older period and shows up in your current 1099-DA, you may be counting the same transaction twice. It happens more than you’d expect during the transition from old crypto reporting to the new 1099-DA regime.
Staking, Airdrop, and Fork Income Counted Twice
Some brokers report staking rewards or airdrops as proceeds on your 1099-DA rather than (or in addition to) as income. If you’ve already counted that income as ordinary income and now it’s appearing again as a sale — you’re looking at double-counting.
Exchange Errors (Yes, Just Errors)
The 1099-DA is new. The IRS finalized regulations late. Exchanges built their reporting pipelines under deadline pressure. Errors happen. Duplicate rows, wrong ticker symbols, incorrect dates, transactions attributed to the wrong customer. This isn’t theory — these are actual error patterns documented during the first 1099-DA filing season.
An Example: From $280,000 to $18,000
Here’s an anonymized composite of what we see regularly.
A trader received a 1099-DA showing $280,000 in proceeds. Based on that form, their tax software estimated a federal tax bill of roughly $55,000. They were not having a good week.
When we went through their actual transaction history:
- $180,000 of the proceeds came from ETH they originally bought in 2020 and 2021. The exchange had no cost basis on file because the ETH was transferred in from a self-custody wallet. Basis reported: $0. Actual cost basis, reconstructed from on-chain data and purchase records: $162,000.
- $40,000 in proceeds was from two transfers between their own wallets that the exchange had categorized as sales.
- The remaining $60,000 in proceeds had basis of approximately $51,000.
Actual net gain after reconstruction: roughly $27,000. Tax bill, after applying the correct long-term rates: closer to $4,000. The 1099-DA wasn’t lying about the proceeds number — proceeds were real. The problem was entirely in what wasn’t reported alongside them.
This is not a rare outcome. It’s a common one. The 1099-DA is a starting point, not a final answer.
If your situation looks like this, our 1099-DA cost basis correction service is specifically built to work through it.
How to Verify Your Actual Numbers
Before you do anything else, gather the source data.
Step 1: Pull Your Full Transaction History
Every exchange you’ve ever used. Every wallet. Every year. If you traded on FTX before it collapsed, request records from the bankruptcy estate or use whatever CSV exports you saved. On-chain history is always available if you have your wallet addresses — block explorers like Etherscan will show every transaction.
Step 2: Identify Every Acquisition
For each sale on your 1099-DA, you need to know:
- When you acquired the asset
- What you paid (price × quantity + fees)
- Where you acquired it
This reconstruction work is tedious. It’s also the difference between paying the right amount and overpaying by tens of thousands of dollars.
Step 3: Match Sales to Lots
Once you have acquisition data, match each sale to the specific lots you’re disposing of, using whichever cost basis method you’re applying consistently. FIFO is the default if you haven’t been doing specific ID.
Step 4: Reconcile Against the 1099-DA
Compare your reconstructed gain/loss to what the 1099-DA implies. Note every discrepancy. You’ll need to document the difference when you file.
Step 5: Check for Transfers
Go through every “sale” on the 1099-DA and confirm it was actually a sale. Filter for transfers between your own wallets and flag them for removal.
How to Correct It on Your Return
Your 1099-DA is not your tax return. It’s an information document that gets reported to the IRS, but you report your actual gains and losses on Form 8949, which feeds into Schedule D.
The IRS expects that the numbers on your return may differ from your 1099-DA — especially for crypto. That’s specifically why Form 8949 has columns for adjustments. You report the proceeds from the 1099-DA, enter your actual cost basis, and note any adjustment codes that explain the difference.
Common adjustment codes relevant here:
- Code B — Basis not reported to the IRS (the standard situation for noncovered securities / missing basis)
- Code E — Incorrect basis reported on 1099-B/1099-DA
The IRS provides documentation on Form 8949 at irs.gov/forms-pubs/about-form-8949. Read the instructions before you file.
Do not just leave the form as-is and hope the IRS doesn’t notice the discrepancy. They will notice. The right move is to report everything accurately, document your basis, and explain any differences via the adjustment mechanism Form 8949 was designed for.
A Note on Noncovered Assets
For the 2024 tax year, most crypto is still classified as “noncovered” — meaning brokers are not required to report basis. The full mandatory basis-reporting rules for crypto don’t kick in until 2025 and later, depending on the asset type and broker.
For noncovered assets, your 1099-DA will show proceeds and likely blank (or $0) basis. This is expected. It doesn’t mean the broker made an error — it means the basis is your responsibility to establish and report. Which, honestly, it always was.
Frequently Asked Questions
Q: Do I have to report my crypto even if my 1099-DA is wrong?
Yes. You report your actual gains and losses on Form 8949. If the 1099-DA is wrong, you correct it through the adjustment columns — you don’t skip reporting because the form is incorrect. The IRS received a copy of your 1099-DA. Your return needs to account for it.
Q: My broker shows $0 cost basis. Can I just use that and take the huge loss… wait, that makes a huge gain. Can I dispute it with the broker?
You can contact your broker to correct errors, but for missing basis on noncovered assets, the broker isn’t reporting basis in the first place — there’s nothing to dispute. You need to reconstruct your actual basis from your own records and report it correctly on Form 8949. The broker’s $0 is a placeholder, not an official IRS position on your basis.
Q: What if I genuinely can’t find my original purchase records?
This happens. On-chain transactions for self-custody wallets are recoverable via block explorers. For exchange purchases from defunct platforms, some records may be accessible through bankruptcy proceedings or old emails/statements. In cases where records are truly unrecoverable, there are documented methodologies for establishing basis under those circumstances — this is where working with a professional who knows crypto becomes worth the cost. Guessing isn’t a strategy.
Q: Will the IRS automatically come after me if my return doesn’t match my 1099-DA?
A mismatch alone doesn’t trigger an audit. But an unreported 1099-DA, or a return where proceeds are omitted entirely, is a different story. Report the proceeds, document your basis, use the correct adjustment codes, and you’ve done your job correctly. A well-documented Form 8949 is your protection.
Q: Can I use a different cost basis method than my broker used?
Yes, with conditions. You can generally use specific identification, FIFO, or other permitted methods — but the method should be applied consistently, and for specific ID, you need to have documented your lot selections at or before the time of sale. Retroactively assigning favorable lots isn’t compliant. If you’ve been inconsistent, that’s something to work through before filing.
Q: What if some of my sales are missing from my 1099-DA entirely?
Report them anyway. You are required to report all taxable dispositions, not just the ones that appear on your information return. Sales that happened on DEXs, through DeFi protocols, or on exchanges that didn’t file 1099-DAs still generate taxable events. Missing from the form ≠ exempt from tax.
Q: Is there a deadline to correct a 1099-DA after filing?
If you filed and later realize your return was wrong — either because you discovered missing basis or because the broker issued a corrected form — you can file an amended return using Form 1040-X. Generally you have up to three years from the original filing deadline to amend. Earlier is better; don’t sit on it.
The Short Version
Your 1099-DA is probably not trying to deceive you. It’s reporting what the broker knows, which is often just the proceeds side of the transaction. When basis is missing — because of transfers, self-custody, pre-2023 acquisitions, or noncovered-asset rules — the implied gain is overstated. Sometimes dramatically.
The fix is documentation. Reconstruct your acquisitions, match them to your sales, and report the corrected figures on Form 8949. The IRS’s own form has the mechanism for this built in.
If the reconstruction is complex — multiple wallets, cross-chain history, DeFi activity, transfers between exchanges — that’s the kind of work we do. Start with our insights hub for more on how crypto tax reporting actually works, then reach out if you need hands-on help.
This post is for educational purposes and does not constitute tax advice. Crypto tax rules are complex and fact-specific. 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.
