Direct answer
If your 1099-DA shows zero or missing cost basis, do not panic and do not assume the form is automatically wrong. Treat it as a risk signal. The broker may have reported proceeds but not enough basis information. Before you file, gather your purchase records, wallet history, transfer records, and exchange exports so you can calculate or review your actual basis carefully.
Form 1099-DA is used by brokers to report digital asset proceeds from broker transactions and, in some cases, basis, to both taxpayers and the IRS. For many 2025 digital asset statements, the IRS says basis may not be included, so taxpayers may need to calculate basis themselves to determine gain or loss.
Why a zero or blank cost basis matters
Cost basis is generally what you paid for the asset, adjusted where needed for fees, transaction costs, or other tax-related details. When basis is missing, your tax software may not know what you originally paid. When basis is shown as zero, the software may treat the full sale amount as potential gain unless you enter or reconcile the missing data.
That does not mean the broker lied. It also does not mean the IRS has already decided your basis is zero. It means there may be a reporting gap between what the broker knows and what actually happened across your wallets, exchanges, and transaction history.
Wallet-transfer example
Imagine you bought 1 ETH on Exchange A in 2022 for $1,400 plus fees. Later, you transferred that ETH to your MetaMask wallet. In 2025, you moved 0.5 ETH from MetaMask to Exchange B and sold it for $2,000.
Exchange B may report the 2025 sale because it handled the sale, but it may not know that you originally bought the ETH on Exchange A. If you file using only the blank basis, your software might treat the full $2,000 as gain. If your records show that the 0.5 ETH had a real purchase cost, your gain calculation may be different.
Records to gather before filing
Collect exchange CSV exports, wallet transaction history, purchase confirmations, transfer records, deposit and withdrawal timestamps, transaction hashes, gas-fee records where relevant, prior-year reports, and any notes about gifts, mining, staking, airdrops, rewards, or business payments.
Screenshots can help as backup, but they should not be your only proof. The goal is not to force a number. The goal is to rebuild a supportable record trail before filing.
Common mistakes
Do not assume blank basis means zero basis. Do not assume the 1099-DA is always wrong. Do not ignore wallet-to-exchange transfers. Do not delete fee data from your exports. Do not mix up proceeds and gain. Most importantly, do not wait until filing day to start reviewing records.
Recommended next step
If your calculator result shows medium or high risk, organize your records and use the best matching Digital Echoes fix before the problem gets more expensive.
FAQ
Does a zero basis on Form 1099-DA mean I owe tax on the full sale amount?
Not automatically. A zero basis should not be assumed unless the asset actually had a zero basis. If you paid for the asset or acquired it in a way that created basis, you may need to reconstruct your records before filing.
Why is my 1099-DA missing cost basis?
Your broker may not know your original purchase price, especially if the asset was transferred in from another exchange, wallet, or DeFi platform. For many 2025 digital asset statements, basis may not be included.
Can crypto tax software fix missing basis automatically?
Crypto tax software can help, but it depends on the data you give it. If you do not import the original exchange, wallet, or transfer history, the software may still show missing or zero basis.
What should I do before filing?
Estimate the mismatch risk, gather supportable records, request corrections if needed, and confirm your final reporting with qualified tax guidance.
Official sources to check
Important disclaimer
This guide is for general education and planning only. It does not provide legal, tax, financial, accounting, immigration, veterinary, customs, or professional advice. Confirm important decisions with the relevant official source or a qualified professional.