CryptoTax UK · Guide
What crypto tax records does HMRC require you to keep?
Incomplete records are one of the biggest problems UK crypto investors face at tax time — and HMRC's requirements are more detailed than most people realise. Whether you traded five times or five thousand times, the record-keeping obligation is the same. This guide tells you exactly what you need to keep and for how long. Educational only — not tax advice.
Organise my records and calculate my tax →What HMRC requires for every transaction
For every cryptoasset transaction, HMRC requires you to record: the type of cryptoasset (e.g. Bitcoin, Ethereum); the date of the transaction; the number of units bought or sold; the value in GBP at the time of the transaction; the cumulative total of units held after the transaction; bank statements and wallet addresses if relevant; and exchange statements or receipts. This applies to every disposal — including crypto-to-crypto swaps, spending crypto, and gifting.
How long must you keep records?
HMRC requires you to keep records for at least 5 years and 10 months after the end of the relevant tax year — effectively for 6 years. For example, records for the 2024/25 tax year (ending 5 April 2025) must be kept until at least January 2031. If HMRC opens an investigation, you will be required to produce these records. Failure to keep adequate records is itself a compliance breach, separate from any tax error.
Getting GBP values for every transaction
For UK tax purposes, every transaction must be valued in GBP at the time it occurred. For transactions on GBP pairs, this is straightforward. For USD or other fiat pairs, you must convert using the exchange rate at the time of the transaction. For crypto-to-crypto swaps with no direct GBP pair, HMRC accepts the GBP equivalent calculated via any intermediate currency, supported by evidence from a reputable source such as your exchange, CoinGecko or CoinMarketCap.
Records for staking, airdrops and income
For income-taxable crypto (staking rewards, mining income, airdrops received for services), you must record the date received, the type and quantity of tokens, and the GBP market value on the date of receipt. These values become your cost basis for any future CGT calculation when you dispose of those tokens. Many investors fail to record income crypto at receipt and later struggle to establish their cost basis accurately.
What to do if your records are incomplete
If you are missing historical records, take the following steps: contact your exchanges directly — most platforms retain records for at least 5–7 years and can provide complete history on request; use a blockchain explorer to reconstruct on-chain transactions using your wallet addresses; use historical price data from CoinGecko or CoinMarketCap to value transactions where GBP values are missing; and document your reconstruction methodology clearly. Reasonable estimates with documented methodology are significantly better than no records at all.
Frequently asked questions
My exchange has closed and I can't get my records — what do I do?
If an exchange has closed, try to access any email confirmations or trade confirmations you received at the time. For on-chain assets, use a blockchain explorer with your wallet addresses to reconstruct activity. For missing cost bases, HMRC expects reasonable estimates based on available market data — document your approach carefully.
Can I use my bank statements as crypto tax records?
Bank statements showing GBP payments to exchanges are useful supporting evidence but are not sufficient on their own. They show money in and out but not the specific crypto assets purchased, prices, quantities or exchange transactions. You need exchange records alongside bank statements.
Does a crypto tax calculator automatically satisfy HMRC record-keeping requirements?
A good crypto tax calculator creates a structured record of your transactions that significantly helps meet HMRC requirements. However, you should also retain the underlying source data — your exchange exports, wallet records, and bank statements — as HMRC may ask to see the raw data behind any tax calculation.
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Organise my records and calculate my tax →Educational guidance only. CryptoTax UK is not a regulated tax adviser and the information above does not constitute tax, legal or financial advice. Always confirm your specific position with HMRC or a qualified accountant before filing.