Crypto taxes: what records to keep

Why records matter more for crypto

With a brokerage account, the broker usually reports your gains to the tax authority and sends you a summary. Crypto is catching up, but you are often on your own: coins move between exchanges and wallets, and no single company sees the whole picture. If you cannot show what you paid for something, a tax authority may treat the whole sale price as profit.

Reporting is increasing. In the US, brokers report crypto sales on Form 1099-DA, starting with sales made in 2025, and for assets acquired from 2026 onwards they report cost basis too. In the EU, the DAC8 directive has required crypto-asset service providers to collect customer transaction data for tax authorities since January 2026, and the UK began collecting similar data under the OECD’s Crypto-Asset Reporting Framework on the same date.

Events that usually count

The details vary, but in many countries, including the US and the UK, these are the events that matter.

• Selling crypto for money. A gain or loss: the proceeds minus what the coins cost you, including fees.
• Swapping one crypto for another. Usually treated as selling the first at its market value and buying the second. Swapping into a stablecoin counts too.
• Spending crypto on goods or services, which is a disposal at the value of what you bought.
• Receiving crypto as income: wages, payment for work, mining and, in many places, staking rewards and some airdrops. These are taxed as income at their value when received, and that value becomes their cost for any later sale.
• Gifts and donations, which have their own rules in most countries.

Moving coins between wallets and accounts you own is generally not a disposal. Record it anyway, because those records are how a coin’s original cost follows it from one place to the next.

What to record for every transaction

• The date and time, ideally in UTC, or with the time zone noted.
• The type: buy, sell, swap, transfer, income, fee or gift.
• The asset and amount on each side, and the network.
• The value in your own currency at that moment, and where the price came from.
• Fees, and what they were paid in. A fee paid in crypto, such as gas paid in ETH, can itself be a small disposal.
• The transaction ID, the addresses or accounts involved, and the exchange or app.
• A short note of what it was for, such as “moved to hardware wallet” or “payment for invoice 42”.

For income and swaps, the value at the time is what counts. Our historical price lookup gives a coin’s daily closing price in US dollars for any date we have, which helps fill gaps. Your tax authority may expect a particular source or method, so pick one and use it consistently.

Cost basis and matching

When you sell part of a holding bought at different prices, the rules decide which purchase you are selling. The US lets taxpayers identify specific units, with first in, first out as the default, and since 2025 it expects cost to be tracked separately for each wallet or account. The UK pools holdings at an average cost, with special rules for coins bought back within 30 days of a sale. Different methods produce different gains, so record every purchase separately with its own cost.

The average cost calculator works out a pooled average across several purchases, and the profit calculator shows the gain on a sale after fees on both sides. Neither replaces your country’s matching rules.

Keeping the trail

1. Download the full transaction history from every exchange you use, at least once a year and always before closing an account.
2. Keep a list of your own wallets and addresses, noting which exchange withdrawals went to which wallet.
3. Record self-custody transactions as they happen. A wallet’s history shows amounts, but not their value at the time or why you sent them.
4. Keep everything for as long as your tax authority can ask for it, which is several years in most countries.

A Wardcrest portfolio keeps a ledger of buys, sells and transfers with their fees, imports CSV files from spreadsheets and other trackers, and exports them on paid plans. It is a record-keeping aid, not a tax calculator.

Record losses too

Record losses as carefully as gains. In many countries a loss on a sale can reduce the tax due on other gains, while a token that has become worthless, or funds lost to a hack or a scam, may be treated differently again. Keep the evidence: transaction IDs, messages and any police or fraud report.