How to Do Crypto Taxes in 2026: A Step-by-Step Guide

Before You Start: What You Will Need

Filing crypto taxes accurately requires a complete record of every transaction you made in the tax year: every purchase, sale, swap, transfer, staking reward, and DeFi interaction. The IRS requires you to know the date of each transaction, what you received or disposed of, the fair market value at the time, and your cost basis in the asset sold. Missing any of these for a transaction means either estimating (risky) or defaulting to zero cost basis (expensive).

Gather records from every platform where you held assets in the tax year: centralized exchanges (download transaction history CSVs), DeFi wallets (blockchain history is public but needs parsing), and staking platforms. If you moved assets between wallets or exchanges during the year, document those transfers now. They are not taxable events, but failing to match them as internal transfers creates phantom gains when software assumes every inbound transaction is a purchase from the market.

Step 1: Collect Your Transaction History

Log into every exchange where you traded or held crypto in the tax year and export transaction history. Most major exchanges offer CSV exports going back several years. Download the complete history, not just the current year, because cost basis for assets you are still holding may trace back to purchases from prior years.

For DeFi activity, you need your wallet addresses. Blockchain explorers like Etherscan (Ethereum), Solscan (Solana), and BscScan (BNB Chain) provide complete transaction history by address. Crypto tax software can pull this data directly if you enter your addresses.

Step 2: Import Into Tax Software

Manual calculation of capital gains is feasible for a small portfolio with a handful of trades. For anything more, software is the practical choice. Koinly imports from exchanges and wallet addresses, classifies transactions automatically, calculates gains under your chosen cost-basis method, and generates Form 8949 and Schedule D.

After importing, review the imported transactions for accuracy. The most common issues are: internal transfers between your own wallets flagged as disposals (generating phantom gains), staking reward values that do not match records, and DeFi interactions classified as swaps when they were deposits or withdrawals. Flag and correct these before proceeding.

Step 3: Choose a Cost Basis Method

Cost basis method determines which specific purchase lots are assigned to a sale when you have multiple purchases of the same coin at different prices. Options include:

• FIFO (First In, First Out): The oldest purchase lots are sold first. Default method if you do not make an election. Can result in more long-term capital gains in a rising market.
• HIFO (Highest In, First Out): Sells the highest-cost lots first, minimizing taxable gains in any given period. Currently allowed by the IRS for crypto as a specific identification method.
• LIFO (Last In, First Out): Less commonly used for crypto; can create short-term gains in a rising market.
• Specific Identification: You choose which lot is sold at the time of each transaction. Requires contemporaneous documentation but allows optimized tax management.

You must apply the same cost basis method consistently throughout the tax year. HIFO typically minimizes current-year tax liability in a bull market. FIFO can be more advantageous in some situations involving long-term gains rates. Run your portfolio through both methods in your tax software before committing, and verify which method your software defaults to before generating reports.

Step 4: Generate Form 8949

Form 8949 lists every capital asset disposal: the asset description, dates of acquisition and sale, proceeds, cost basis, adjustments, and gain or loss. Crypto tax software generates this form automatically. If you have hundreds or thousands of transactions, the software aggregates them and allows you to attach a supplemental statement rather than entering every line manually.

Short-term disposals (held less than one year) go in Part I of Form 8949 and feed to Schedule D Line 1. Long-term disposals (held more than one year) go in Part II and feed to Schedule D Line 8. The holding period starts the day after you acquire the asset and ends on the day of sale.

Step 5: Report Income

Staking rewards, yield farming income, and mining income are reported as ordinary income, not capital gains. These amounts belong on Schedule 1 (Additional Income) as “other income,” or on Schedule C if your crypto activity rises to the level of a business. The fair market value at receipt is both your income and your cost basis in the new tokens.

Your exchange may issue a 1099-MISC or 1099-DA for income above certain thresholds. Even without a 1099, the income is taxable and must be reported. The IRS matching program compares 1099 forms to reported income; unreported income, even small amounts, creates correspondence audits.

Step 6: Complete Schedule D and File

Schedule D summarizes your total capital gains and losses from Form 8949. Net short-term gains or losses combine with net long-term gains or losses. The net result flows to Form 1040. If you have net capital losses after offsetting all gains, up to $3,000 per year reduces ordinary income; excess carries forward to future years.

Most tax software (TurboTax, H&R Block, FileYourTaxes.com) imports Form 8949 data from crypto tax exports and populates Schedule D automatically. Verify the totals match before submitting. The most common error at this stage is a mismatch between what the crypto tax software calculated and what the filing software imported, usually caused by format incompatibility in the CSV export.

Common Mistakes

Failing to report DeFi rewards because no exchange issued a 1099 is the most consistent error. The IRS does not require a 1099 to consider income taxable. Treating internal wallet-to-wallet transfers as taxable disposals is the second most common error, and it overstates gains. Using zero cost basis on assets purchased before transaction history was available understates the basis and overstates gains. Software that pulls blockchain history can recover historical purchases even when exchange records are incomplete.

If you have crypto activity from multiple years and missed reporting prior years accurately, a voluntary amended return (Form 1040-X) for the affected years is the appropriate path before the IRS identifies the discrepancy through third-party reporting.

Marko Jambrek

Licensed architect in Zagreb, 30 years of practice (Vastu + sustainable design). Writes about AI tools through a lens of order and long-term value, tests before recommending.