How to Track Your Cost Basis and Crypto Records
By moonbag.info team · · Beginner
Your cost basis is what you paid for an asset, including fees. When you sell, your gain or loss is roughly the sale proceeds minus that basis. Without good records, you can’t calculate gains accurately, you may overpay tax, and you’ll struggle to answer questions if they come up. Good record keeping is boring, but it’s one of the most valuable crypto habits.
This guide is general and US-centric. Consult a tax professional for your situation.
What to record
For every purchase
- Date and time
- Asset and quantity
- Price per unit and total paid
- Fees paid
- Platform or wallet
- Transaction ID (if on-chain)
For every sale or swap
- Date and time
- Asset and quantity sold
- Proceeds (in dollars at the time)
- Fees
- What you received (dollars, a stablecoin or another token)
- Which lots you sold, if you use specific identification
Remember that in the US, swapping one token for another is generally a taxable event, and the token you receive gets a new cost basis equal to its fair market value at the time.
For every transfer
- Date
- From where and to where
- Asset, quantity and transaction ID
- Network fee paid
Transfers between your own wallets aren’t sales, but you need them to connect the history: when you later sell on a different platform, you have to show where those units came from and what they cost.
For income
Staking rewards, mining, airdrops and crypto received as payment are generally income in the US. Record the date and fair market value when received; that value becomes the basis.
A simple spreadsheet layout
| Date | Type | Asset | Qty | Price | Total $ | Fee $ | From | To | Tx ID | Notes |
|---|---|---|---|---|---|---|---|---|---|---|
| 2026-01-05 | Buy | Token A | 100 | $10.00 | $1,000 | $5 | Bank | Exchange 1 | — | DCA #1 |
| 2026-02-05 | Buy | Token A | 80 | $12.50 | $1,000 | $5 | Bank | Exchange 1 | — | DCA #2 |
| 2026-02-20 | Transfer | Token A | 180 | — | — | $2 | Exchange 1 | Wallet 1 | 0xabc… | To cold storage |
| 2026-06-10 | Sell | Token A | 50 | $20.00 | $1,000 | $5 | Wallet 1 | Exchange 2 | 0xdef… | Ladder rung 1 |
(Illustrative.) Keep one row per event, and don’t delete rows; add correcting entries instead.
Calculating basis per lot
From the example:
- Lot 1: 100 units, $1,005 total ($10.05 per unit including fee).
- Lot 2: 80 units, $1,005 total (about $12.56 per unit).
If you sell 50 units under first-in, first-out (FIFO), they come from Lot 1: basis about $502.50. If you specifically identify Lot 2 (where allowed and properly documented), basis is about $628. The transfer fee’s treatment can vary; ask a tax professional.
Since 2025, the IRS has required lot tracking on a wallet-by-wallet (or account-by-account) basis rather than one pooled total across everything you own. That makes transfer records even more important.
Step-by-step: getting organized
- List every place you’ve held crypto: exchanges, wallets and apps, including ones you no longer use.
- Download transaction histories (usually CSV files) from each exchange. Do this regularly; closed or failed platforms may not give you a second chance.
- Export wallet histories from block explorers or wallet apps using your public addresses.
- Combine everything into your spreadsheet or a tracking tool.
- Match transfers. For each withdrawal from one place, find the matching deposit somewhere else.
- Fill in missing basis for anything transferred in.
- Reconcile balances. Your records should match what’s actually in each wallet and account.
- Back up your records in at least two places.
Using tracking software
Crypto tax and portfolio tools can import exchange data and wallet addresses and calculate gains. They save time, but:
- Check imports for errors, especially transfers marked as sales or missing basis.
- Give read-only access. If you connect an exchange with an API key, make sure it can’t trade or withdraw. See How to Secure Your Exchange Account.
- Never enter your seed phrase. A tracker only needs your public addresses.
- Keep your own exports too, in case you switch tools.
Broker forms
US brokers are phasing in reporting on Form 1099-DA, starting with gross proceeds for 2025 sales and adding cost basis for certain assets acquired from 2026 onward. If you moved crypto in from a wallet, the broker may not know your basis and may report it as missing. Your own records fill that gap. See Tax-Aware Profit-Taking.
How long to keep records
Keep records for as long as you hold the asset, plus several years after you sell it and file the related return. Many people simply keep crypto records indefinitely.
Common mistakes
- Not recording fees, which affect basis and proceeds.
- Missing transfers, making moved coins look like they came from nowhere.
- Waiting until tax season and finding an old exchange has closed.
- Forgetting swaps are generally taxable.
- Not recording income from staking or airdrops.
- Trusting software imports blindly.
- Losing records in a single file on a single device.
Key takeaways
- Record every buy, sell, swap, transfer and income event, including fees.
- Match transfers between your own wallets and accounts.
- Download exchange histories regularly and back everything up.
- Use tools if they help, but check them, and consult a tax professional.