What Records Should I Keep for Cryptocurrency Transactions

Introduction

Cryptocurrency is treated as a taxable asset in the UK, which means you may need to pay Capital Gains Tax (CGT) or Income Tax on your profits. To calculate this correctly, you must maintain detailed and accurate records of every crypto transaction.

HMRC does not receive all your crypto data automatically from exchanges, so you are responsible for keeping your own records. Without proper documentation, you may find it difficult to justify your tax calculations if HMRC opens an enquiry.

Why crypto record keeping is important

HMRC expects crypto investors to maintain clear records showing how gains and losses were calculated. These records must include the date, type, quantity, and value of every crypto transaction in pounds sterling.

Accurate records help you:

Calculate your taxable gains or losses under HMRC’s share pooling rules.

Track your cost basis (the value you paid for each asset).

Prove ownership of your crypto holdings.

Avoid double-counting transactions or missing disposals.

Defend your figures in case of an HMRC audit.

If you fail to keep adequate records, HMRC may estimate your gains and charge additional tax, penalties, and interest.

What information you should record

For each transaction, you must record the following details:

The type of crypto asset (for example, Bitcoin, Ethereum, or another token).

Date of acquisition and disposal (when you bought, received, sold, or exchanged crypto).

Number of units involved in each transaction.

Value in pounds sterling at the time of the transaction.

Transaction fees or network charges paid.

Wallet addresses and the names of exchanges or platforms used.

Purpose of the transaction, such as buying, selling, swapping, or transferring crypto.

If you receive crypto through mining, staking, airdrops, or as payment for services, record:

The amount of crypto received.

The date it was received.

The market value in pounds at that time.

Any associated costs or expenses, such as electricity for mining.

These details allow you to calculate both Capital Gains Tax (on disposals) and Income Tax (on income-related activities).

How to track wallet-to-wallet transfers

Transferring crypto between your own wallets is not a taxable event, but you still need to record it. These transfers can affect your cost basis and help you prove that you retained ownership.

For every internal transfer, note:

The date and time of the transfer.

The sending and receiving wallet addresses.

The amount of crypto moved.

The reason for the transfer (for example, moving assets to a hardware wallet).

Accurate transfer records prevent HMRC from confusing internal transactions with disposals or sales.

How to value transactions in pounds sterling

HMRC requires all crypto values to be reported in pounds sterling, even if the transaction was conducted in another currency or crypto. You must record the sterling value at the time of each transaction using a reliable exchange rate.

You can use market data from a recognised exchange or a reputable pricing service such as CoinMarketCap or CoinGecko, as long as you apply the same source consistently.

Always note the source of your valuations in case HMRC requests verification.

Using software to record transactions

Keeping manual records for every crypto trade can be time-consuming, especially if you use multiple exchanges. Crypto tax software can automate the process by importing your transaction data and converting it into HMRC-compliant reports.

Popular tools used by UK investors include:

Koinly

Recap

CoinTracker

Accointing

These platforms automatically convert transactions into pounds, apply HMRC’s pooling and 30-day rules, and generate reports that can be shared with your accountant or uploaded to your Self Assessment tax return.

However, even if you use software, you are still responsible for checking the data is complete and accurate.

How long to keep your crypto records

HMRC requires individuals to keep financial records for at least five years after the Self Assessment submission deadline for the relevant tax year.

For example, if you file your 2024 25 tax return by 31 January 2026, you must retain records until at least 31 January 2031.

If you run a business or trade professionally, you may need to keep records for six years or longer.

Keeping your records indefinitely is often a good idea, especially if you plan to hold crypto long-term or trade regularly.

Common record keeping mistakes to avoid

Not converting values into pounds sterling at the time of each transaction.

Failing to record wallet addresses or transaction IDs.

Ignoring airdrops, staking rewards, or referral bonuses as taxable income.

Losing access to old exchange data after a platform closes or restricts accounts.

Not distinguishing between transfers and disposals.

Maintaining detailed and organised records reduces the risk of errors and penalties.

Example scenario

Alice buys 2 Ethereum on Binance for £1,200 each, paying £20 in fees. She records the total cost as £2,420. She later swaps 1 Ethereum for Bitcoin worth £2,000. Her records show:

Purchase: 2 ETH for £2,420 on 10 May 2023.

Disposal: 1 ETH worth £2,000 on 15 December 2023.

Gain: £2,000 £1,210 (average pooled cost per ETH) = £790.

Because Alice keeps detailed records, she can report her Capital Gains Tax accurately to HMRC and support her calculations if ever questioned.

Best practices for storing records

Use spreadsheets: Record all your transactions in Excel or Google Sheets, including exchange rates and wallet addresses.

Backup regularly: Store your files securely in multiple locations, such as cloud storage and encrypted drives.

Download exchange reports: Save copies of annual summaries and CSV exports from every exchange you use.

Label transactions clearly: Add notes explaining each transaction’s purpose to avoid confusion later.

Good organisation now will save you time and stress during tax season or if HMRC requests information.

Conclusion

Keeping accurate records of cryptocurrency transactions is not optional under HMRC rules. You must document every purchase, sale, swap, and transfer, along with their values in pounds sterling. These records are vital for calculating your gains, losses, and taxable income correctly.

By keeping comprehensive, well-organised records and using reliable crypto tax tools, you can meet your legal obligations, simplify your reporting, and reduce the risk of penalties. If your crypto activity is extensive or involves multiple exchanges, seek advice from an accountant familiar with digital assets and HMRC compliance.