Crypto Cost Basis and Record Keeping

The short answer

Because digital assets are treated as property, disposing of them generally requires working out what you received and what the asset had cost you. Cost basis is the 'what it cost you' side of that calculation, and record keeping is how you can still establish it years later.

Educational information only. This page is not tax or legal advice, does not cover your circumstances, and does not replace a qualified professional or the IRS's own current instructions.

The core terms

• Cost basis — generally what you paid to acquire an asset, including certain acquisition costs. It is the starting point for calculating gain or loss on a later disposal.
• Proceeds — what you received when you disposed of the asset, measured in US dollars at that time.
• Gain or loss — the difference between proceeds and basis on a disposal.
• Holding period — how long you held the asset before disposing of it. US rules distinguish short-term from long-term holdings, and the distinction affects how a gain or loss is treated.
• Taxable event — a transaction the rules treat as reportable. Acquiring and simply continuing to hold is generally not one; disposing generally is.
• Fair market value — the US dollar value of an asset at the moment of a transaction, which is what makes a crypto-for-crypto trade measurable at all.
• Income versus capital treatment — assets received as compensation, or as a reward, are generally accounted for differently from assets you bought and later sold. The IRS addresses these categories separately.

Why 'I never cashed out to dollars' does not settle it

A frequent misunderstanding is that only a conversion to dollars matters. Under property treatment, exchanging one digital asset for another is a disposal of the first asset, measured in dollars at that moment, even though no dollars moved. Spending crypto on goods or services works the same way.

This is exactly why records matter: a year of small swaps produces a long list of events, each needing a dollar value at the time it happened, and exchanges do not always retain that history for you.

Transfers between your own wallets

Moving an asset between wallets you control is a change of location, not a change of owner. It does not by itself create a disposal — but it does break the audit trail if you do not record it, because the receiving platform sees an incoming asset with no acquisition history and the sending platform sees an outflow that can look like a sale.

• Record the date, the asset, the amount, both addresses and the transaction hash for every self-transfer.
• Note the original acquisition details alongside it, so the basis travels with the asset in your own records.
• Network fees paid to move assets should be recorded too; how they are treated is a question for your tax professional.

What to keep, per transaction

• Date and time of the transaction.
• What was acquired or disposed of, and the exact quantity.
• The US dollar value at the time of the transaction, and where that value came from.
• Fees paid, both platform fees and network fees.
• The counterparty platform or the wallet addresses involved, and the transaction hash where one exists.
• The reason for the transaction: purchase, sale, trade, payment received for work, reward, gift, or a transfer between your own wallets.
• Any tax forms the platform issued to you.

Export your full history from every platform at least annually and store it yourself. Accounts get closed, platforms fail, and history that existed for years can become unavailable exactly when you need it.

A worked example of the arithmetic (hypothetical)

The figures below are invented to show the mechanics. They are not market data and do not represent any real price.

1. You buy 1 unit of an asset for $1,000 and pay a $10 purchase fee. Your records show an acquisition with a $1,010 cost.
2. Months later you trade that whole unit for a different asset, when the unit is worth $1,400. That trade is a disposal of the first asset with $1,400 of proceeds, even though no dollars were received.
3. The difference between $1,400 and $1,010 is the gain on that disposal, and the holding period determines how it is characterised.
4. Your basis in the newly received asset starts from its $1,400 value at that moment, which is what you will need when you eventually dispose of it.
5. Everything in this chain depends on you having recorded the dollar value on both dates. Without that, the calculation cannot be reconstructed.

Mining, staking and payment for work: the terminology

Assets received as payment for services, and assets received as rewards from mining or staking activity, are generally treated as income measured in dollars at the time you receive them, rather than as a purchase. The amount recognised then generally becomes the basis for a later disposal, which is why the receipt date and value must be recorded, not just the eventual sale.

The specifics — including timing questions such as when a reward is considered received, and how a particular arrangement should be characterised — depend on facts we cannot assess. Take those to a professional and to the IRS's current guidance rather than to any website.

Losses, theft and scams

The tax treatment of stolen or lost digital assets is fact-specific and has changed with legislation over time, so we do not state a rule here. What is universally useful is evidence: transaction hashes, addresses, dates, the platform or site involved, message threads, and copies of any reports you filed. Report the incident to the FBI's Internet Crime Complaint Center and the FTC, keep the reference numbers, and give the complete record to your tax professional.

Common record-keeping mistakes

• Relying on one exchange's annual statement when assets moved across several platforms and wallets.
• Not recording self-transfers, which later makes ordinary movements look like disposals.
• Losing access to history after an account closure or a platform failure.
• Recording quantities but not the dollar value at the time, which is the part that cannot be reconstructed reliably later.
• Treating crypto-to-crypto trades as invisible because no dollars were involved.
• Assuming small amounts do not need recording, then facing hundreds of unreconstructable entries.

Sources

• IRS: digital assets
• IRS: frequently asked questions on virtual currency transactions
• IRS Notice 2014-21 (digital assets treated as property)
• IRS Publication 551: basis of assets
• FBI Internet Crime Complaint Center