The 1099-DA Form represents one of the most significant changes to crypto tax reporting in years. For the first time in history, the IRS will receive standardized reports of your digital asset sales directly from brokers. This makes accurate tax reporting more important than ever.
So when your 1099-DA arrives, don't stress, but don't ignore it either. The IRS has received the same information, so you must ensure that your tax filing is accurate, with sufficient evidence to support any changes.
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You don't have to navigate this alone. Summ makes 1099-DA reporting simple by automatically tracking your cost basis across all the platforms you use, reconciling your 1099-DA data, and generating IRS-compliant tax forms with accurate gains, efficiently and quickly.
Here’s exactly what to do.
Step 1: Gather All Your 1099-DAs
If you used multiple exchanges, collect every 1099-DA you received. Each form represents transactions from that specific platform. US-regulated exchanges are required to issue Form 1099-DA to customers who dispose of cryptocurrency (e.g, sell) during the financial year.
Step 2: Verify the Information and Identify Discrepancies
Cross-reference each 1099-DA against your own records. Some issues include:
- Blank or $0 cost basis (most common problem)
- Incorrect proceeds amounts
- Wrong transaction dates
- Missing transactions
- Transactions attributed to the wrong asset
What you can find on your exchange:
- Transactions that occurred entirely on that exchange
- Historical prices at the time of your transactions
- Trading fees and other transaction costs
- Deposit and withdrawal records
What you WON'T find on your exchange:
- Cost basis for crypto you transferred INTO the exchange from another platform
- Your complete transaction history from other exchanges or wallets
- DeFi transactions or smart contract interactions
Step 3: Establish Your Accurate Cost Basis with Summ
An efficient way to solve the missing cost basis across all your crypto accounts is to use Summ. Summ can help you import your complete transaction history from all exchanges, wallets, and DeFi protocols you've used, then help calculate accurate cost basis even for assets that have been moved between platforms multiple times.
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Step 4: Correct Errors Using Form 8949
Even though your 1099-DA may show blank cost bases, you should still report the accurate cost basis on Form 8949. This is legal and expected by the IRS during this transition year.
Form 8949 (Sales and Other Dispositions of Capital Assets) is where you can report each crypto sale with accurate cost bases:
| Column |
What to Enter |
| (a) Description of property |
e.g., "1.5 Bitcoin" |
| (b) Date acquired |
Your original purchase date |
| (c) Date sold |
Match your 1099-DA |
| (d) Proceeds |
Match your 1099-DA |
| (e) Cost basis |
The correct amount from Summ |
| (h) Gain or loss |
Proceeds minus cost basis |
Important: The proceeds on your Form 8949 must match what's on your 1099-DA from your exchange. The IRS cross-references this information. Only the cost basis and gain/loss will differ.
Example of how Summ reconciles your 1099-DA:
| Form 8949 (from Summ) |
Amount |
| Proceeds from your exchange sale |
$40,000 |
| Cost basis (tracked from original purchase) |
$30,000 |
| Actual taxable gain |
$10,000 |
Versus what was reported in the 1099-DA from your exchange:
| 1099-DA from your exchange |
Amount |
| Proceeds |
$40,000 |
| Cost basis |
$0 (missing) |
| Implied gain (if not corrected) |
$40,000 |
By using Summ's Form 8949, you report the accurate $10,000 gain instead of potentially being taxed on a phantom $40,000 gain.
How to Handle Form 8949
When you receive a 1099-DA with a blank basis, you must use the new 2025 category codes to reconcile the data:
| If your 1099-DA... |
Check this box on Form 8949 |
What it tells the IRS |
| Shows proceeds but blank basis |
Box H (Short-term) or Box K (Long-term) |
"The broker reported the sale, but I am providing the cost basis myself." |
| Is missing entirely (DeFi/Self-custody) |
Box I (Short-term) or Box L (Long-term) |
"This transaction wasn't on a 1099-DA, but I am reporting it anyway." |
Step 5. Complete Your Tax Filing
Once you have your corrected Form 8949 from Summ:
- Transfer totals to Schedule D: Schedule D (Form 1040) summarizes your total capital gains and losses from Form 8949.
- File your return: Include Form 8949 and Schedule D with your tax return. Answer "Yes" to the digital asset question on Form 1040.
- Maintain documentation: Keep all supporting records for at least 3 years (preferably 6-7 years):
- Transaction history from all exchanges and wallets
- Form 8949 and Schedule D
- Complete calculation showing how you arrived at cost basis
- Your 1099-DA forms from all brokers
If the IRS questions the discrepancy between your 1099-DA proceeds and your reported gains, your documentation proves the cost basis.
What If You've Already Filed Your Crypto Taxes Incorrectly?
If you previously overpaid taxes because of missing cost basis, you can:
- File Form 1040-X (Amended U.S. Individual Income Tax Return)
- Include corrected Form 8949 and Schedule D
- Claim a refund for the overpayment
- You have 3 years from the original filing deadline to amend
Summ can generate amended tax reports for prior years.
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