Guide

Crypto Tax Records for HMRC: What to Keep for Every Trade (2026/27)

Written by James Whitfield · Last checked 18 October 2026 Checked against GOV.UK and the HMRC Cryptoassets Manual

Quick answer

HMRC expects a record of every crypto transaction: the token, the date, the number of units, the value in pounds, how many units you have left, and the pooled cost before and after each disposal, plus bank statements.¹ Exchange reports are not enough, because they do not track your pooled cost. Since 1 January 2026 UK crypto platforms also collect user details and report UK users' transactions to HMRC, with the first reports due by 31 May 2027.³

Key facts

Selling, swapping one token for another, spending crypto and giving it away (except to a spouse, civil partner or charity) are all disposals.¹
Each token type has its own Section 104 pool; same-day and 30-day purchases are matched first.²
The Self Assessment return has had a separate cryptoassets section since 2024/25.⁴
Under the Cryptoasset Reporting Framework, providers report UK-resident users, and other users in CARF countries, to HMRC each year by 31 May.³
2026/27: £3,000 annual exempt amount, then 18% or 24%. Unpaid tax from earlier years can be disclosed through HMRC's Cryptoasset Disclosure Service.¹

What records does HMRC expect for crypto?

GOV.UK says to keep separate records for each transaction in each pool, including:¹

A record for each crypto transaction

Type of token	BTC, ETH, SOL, a stablecoin...
Date of the transaction	The trade date, in UK time
Units bought, received or disposed of	To 8 decimal places if that is how they trade
Value in pounds sterling at the time	From a consistent, reasonable price source
Units held afterwards	So the pool can be checked
Pooled cost before and after any disposal	The figure exchanges do not give you
Bank statements	Showing pounds in and out
Wallet addresses (optional)	Helps prove transfers between your own wallets

Also keep the fees paid on each trade, because exchange fees on buying and selling form part of your cost or reduce your proceeds.

Why isn't my exchange's tax report enough?

GOV.UK is direct about this: transaction reports from exchanges are not tax calculations and do not track your pooled costs, so you must keep your own records.¹ An exchange only sees its own platform. If you moved coins between two exchanges or to a hardware wallet, neither report knows what you originally paid, and many show a cost of zero for coins transferred in. Using those figures can overstate your gain, or understate it if a "cost" is really a transfer fee.

Treat exchange exports as raw data. Combine them into one ledger per token, with transfers between your own wallets marked as transfers, not disposals.

Before you pay HMRC, check every cost, loss and relief is in your figures: get your CGT Check report, £4.99 →

Worked example: one swap, recorded properly

Aisha bought 0.5 BTC in January 2024 for £15,000 and 0.3 BTC in March 2025 for £12,000, fees included. In October 2026 she swaps 0.2 BTC for ETH worth £14,000 at that moment.

Aisha's BTC pool and the swap

BTC pool before the swap: 0.8 BTC	£27,000
Value received for 0.2 BTC (the ETH, in pounds)	£14,000
Less cost from the pool: £27,000 × 0.2 ÷ 0.8	−£6,750
Gain on the swap	£7,250
BTC pool after: 0.6 BTC	£20,250
New ETH pool: the ETH received	£14,000

She never received any pounds, but the swap is a disposal. After her £3,000 allowance, £4,250 is taxable: £765 at 18% or £1,020 at 24%. Her record for this one line needs the date, both tokens, both unit amounts, the sterling value and both pools before and after.

If she had bought BTC again within 30 days, the 0.2 BTC would be matched with that purchase first, not with the pool. The crypto CGT calculator applies the pooling and matching rules.

What does the Cryptoasset Reporting Framework mean for you?

The UK applies the OECD's Cryptoasset Reporting Framework (CARF). Crypto service providers operating in the UK collect details of all their users and report users who are tax resident in the UK, or in another country signed up to CARF, with a summary of their transactions.³ The first reporting period is 1 January to 31 December 2026, reported between 1 January and 31 May 2027.

In practice, your exchange will ask for your tax residence and identifiers, and HMRC will be able to match platform data against Self Assessment returns. That makes accurate records more important, not less: the data HMRC receives will not include your pooled cost, so the burden of showing the right gain stays with you.

What about staking, airdrops and DeFi?

Staking and mining rewards are usually taxed as income when you receive them, at their value in pounds. That value becomes their cost in your pool.
Airdrops received for doing something can be income; unsolicited airdrops usually are not, and may have a nil cost.
Lending and liquidity pools can involve disposals depending on the arrangement. Record every token movement and keep the protocol's terms.

HMRC's Cryptoassets Manual has the detail for each case.²

What if your records are incomplete?

Download every exchange history you can, including closed accounts; many exchanges keep data for years.
Use bank and card statements to fix the pounds you paid in and took out.
Use public blockchain records for wallet-to-wallet transfers.
Make reasonable estimates only where nothing else exists, use a consistent price source, and note how you estimated in the additional information on your return.
Disclose past gains through the Cryptoasset Disclosure Service if earlier years were not reported.¹

How long should you keep crypto records?

For as long as you hold any of the tokens, because a pool can depend on a purchase made years ago, and then for the normal period after the return that reports the final disposal. For an online Self Assessment return filed on time that is at least 22 months after the end of the tax year.⁵ Our CGT records guide covers the rules for all assets, and how to report CGT explains the Self Assessment and real-time routes.

Turn your records into a tax figure

Enter your buys, sells and swaps and the crypto calculator works out the pooled cost and the 2026/27 CGT.

Open the crypto CGT calculator

Frequently asked questions

What crypto records does HMRC need?

For each transaction: the type of token, the date, the number of units, the value in pounds, the number of units left, the pooled cost before and after any disposal, and bank statements. Wallet addresses are useful but optional.

Is my exchange's transaction report enough?

No. GOV.UK says exchange reports are not tax calculations and do not track your pooled cost, so you must keep your own records. Use them as source data.

Will HMRC know about my crypto?

Increasingly, yes. Since 1 January 2026 UK cryptoasset service providers collect details of their users under the Cryptoasset Reporting Framework, and the first reports to HMRC, covering 2026, are due by 31 May 2027.

How long should I keep crypto records?

At least as long as you hold the tokens, plus the normal period after you report a disposal. For Self Assessment that is at least 22 months after the end of the tax year, longer if you file late.

Is swapping one coin for another taxable?

Yes. Exchanging one cryptoasset for another is a disposal, so a gain or loss arises in pounds, even though you never cashed out.

This page is general information, not tax advice. It reflects GOV.UK guidance on cryptoassets and on the Cryptoasset Reporting Framework as checked on 18 October 2026. DeFi and income-type rewards can need specialist advice.

Sources & references

The rates, allowances and rules in this guide are drawn from the official HMRC and GOV.UK sources below, checked for the 2026/27 tax year. Each link opens the relevant government page in a new tab.

Verified against published HMRC and GOV.UK guidance.