A transfer from an exchange to your own wallet is usually not a taxable sale. Recording it as one can duplicate gains, costs and tax due.
Important: this is general educational information, not personal tax advice.
Keep a complete trail for each taxable event and transfer. Record the date, time, asset, quantity, GBP value, fees, wallets, transaction ID and supporting evidence.
For UK Self Assessment, keep records for at least five years after the 31 January filing deadline.
Map the process
List every source first, then build one ledger from it.
Make a source list
Create a Sources tab for every crypto source used during the tax year. Include each exchange, wallet address, hardware wallet and browser wallet.
Also list each DeFi protocol, NFT marketplace and bank account that touched crypto. Add the date range beside every source.
The usual error is forgetting an old exchange account with a small balance.
Set a folder structure
Keep one folder for each tax year. Store original CSVs, wallet evidence, DeFi records and GBP prices separately.
Keep bank evidence and calculations in their own folders too. This makes later checks much faster.
Use the original export file where possible. A copied spreadsheet can hide missing columns or changed values.
For the 2024-25 tax year, a Self Assessment return is normally due by 31 January 2026. Keep records until at least 31 January 2031. That is five years after that filing deadline.
Your source list now shows where each record should come from. Next, capture every movement in one consistent format.
Capture every movement for HMRC
Record the same core fields for every movement, including transfers that create no tax.
Fill these fields every time
Use one master ledger for every crypto movement. Record the date, time, asset, amount, GBP value and price source.
Also record fees, location, transaction reference and counterparty where known. Add a tax label, such as purchase, disposal, own transfer, income receipt or fee.
A ledger row without a GBP value often causes the longest delay later.
Save proof for unusual events
A token swap is normally a disposal of the token you give up. It is also an acquisition of the token you receive.
Record rewards, mining income, airdrops, lending interest, crypto payments and NFT sales separately. An initial receipt may be income.
A later sale can then create a capital gain. Keep proof for both events.
Use this simple ledger model
| Event | Evidence to save | Ledger treatment |
|---|
| BTC purchase | Order CSV, GBP payment, fee | Acquisition and cost basis |
| Wallet transfer | Withdrawal ID, TXID, receiving address | Own transfer, not a new purchase |
| ETH to token swap | DEX TXID, token amounts, GBP price | ETH disposal and token acquisition |
| Crypto sale for GBP | Trade report, fee, bank withdrawal | Disposal for capital gains calculation |
Understand CARF data and your own responsibilities
The Crypto-Asset Reporting Framework, or CARF, can increase tax-authority visibility of crypto activity. It applies to activity conducted through reporting crypto-asset service providers.
Depending on reporting rules and the platform's role, an exchange may hold identifying details. It may also hold account information, transaction history, asset balances and proceeds data.
That does not create complete HMRC crypto records for you.
Platform data may not show that two wallets belong to you. It may not show the original crypto cost basis of transferred assets either.
It may also omit your GBP valuation method. It may not show whether a movement was an own-wallet transfer or a crypto disposal.
Keep your own exchange CSV exports and wallet addresses. Keep blockchain TXID references, GBP transaction values and classification notes too.
Then compare them with any platform statements. That comparison exposes missing transfers before you calculate tax.
Match your own-wallet transfers
Link both sides of each own-wallet transfer before calculating gains.
Match six details
Match the asset, quantity, sending time, receiving time, destination address and TXID. These six details normally identify one transfer.
If the receiving amount is lower, check whether a network fee caused the difference. Do not treat it as an unexplained loss.
Label linked entries as an own-wallet transfer. Do not label them as a sale and new purchase.
Review the false-transfer traps
A transfer to another person is not your own transfer. A merchant payment or NFT purchase is not one either.
Bridges, wrapped tokens, liquidity pools and lending platforms need separate review. Legal rights and received assets may change.
This looks simple in theory, but bridges can create the hardest records. The same person may start the transaction, yet receive a different asset.
Transfer matching flow
Exchange withdrawal
CSV reference
→
Check TXID
asset and time
→
Wallet deposit
your address
→
One linked transfer
not sale plus purchase
Document DeFi and NFT activity separately
DeFi transaction records need more detail than a standard exchange trade. One wallet interaction can include several assets, approvals and protocol receipts.
For a bridge, record the asset sent and asset received. Also record the destination chain, bridge transaction hash and any wrapped-token relationship.
Do not assume it is an own-wallet transfer because you started it. The asset or legal right may have changed.
For liquidity pools, lending and staking, save the protocol screen and smart-contract address. Save token amounts, receipt or LP tokens, rewards, withdrawals and each crypto transaction fee.
Record token swaps with both sides of the swap. Keep a defensible GBP value for the relevant time.
For NFTs, keep the marketplace order, token ID and collection. Keep wallet addresses, royalty and marketplace fees, plus the TXID.
These records help you identify income receipts, acquisitions and later disposals consistently. The next step is to check whether your ledger balances before filing.
Reconcile records before self assessment
Check balances, duplicates, fees and GBP values before entering any tax figure.
Run four checks in order
Find duplicate rows caused by API and CSV imports. Then match transfers between accounts and wallets you control.
Identify entries without GBP values or evidence. Check that every fee is recorded.
Review income separately from capital gains. Rewards or mining receipts may be taxable when received.
They can become acquisitions for later disposal calculations. This split is easy to miss when one report mixes all transactions.
Keep an audit trail after filing
Save the submitted return, gain calculations, income schedule and ledger version together. Save the source files in the same place.
Add notes for unusual classifications and matched transfers. A short note can explain a transaction months later.
Keep a transaction-level ledger for every crypto disposal and income receipt. Match transfers between addresses you control before calculating tax. For UK Self Assessment, keep the ledger, exports, TXIDs, GBP pricing evidence and calculations for at least five years after the 31 January filing deadline. This gives HMRC a clear explanation where exchange data is incomplete.
⚠️ Do not delete old wallet addresses after moving funds. A zero balance may still prove where an acquisition cost or transfer came from.
Rebuild incomplete crypto tax records
If an exchange closed or an export is missing, rebuild the ledger before estimating anything. Start with the strongest evidence available.
Start with blockchain explorers and the relevant wallet transaction ID or blockchain TXID. Then collect archived exchange emails, trade confirmations and bank or card statements.
Also collect deposit and withdrawal references, tax-software imports, screenshots and notes made at the time. These sources can support a missing history.
Prioritise high-value disposals, income receipts and entries without GBP values. These create the greatest risk for capital gains calculations or a Self Assessment crypto return.
Mark each reconstructed figure clearly. Keep the source and date for every estimate.
Do not use a current token price for a historic event. If you cannot support the acquisition date or cost basis, preserve that uncertainty.
Get tailored advice before filing where the evidence remains incomplete. Your completed audit trail makes that advice far more useful.
Questions & answers
Do I get taxed on crypto in the UK?
Crypto can create capital gains tax, income tax or both. Selling, swapping or spending crypto can be a disposal.
Staking rewards, mining income and some crypto payments may be income when received.
How long must I keep crypto tax records?
Keep records for at least five years after the 31 January filing deadline. For 2024-25, if filed by 31 January 2026, keep them until at least 31 January 2031.
Can HMRC use exchange data instead of my records?
No, exchange data does not normally explain wallet ownership, cost basis or transfer purpose. Keep CSV exports, TXIDs, GBP valuations and calculations.
How do I add crypto to my tax return?
Report taxable crypto gains and income through Self Assessment. Support the figures with your transaction ledger.
Keep income separate from capital gains disposals.
Keep your records ready for HMRC
Save the evidence now, while every account and wallet remains accessible.
The essentials: record each crypto movement with its GBP value, fee, source and evidence link.
Match both sides of every own-wallet transfer. This stops it being counted as a sale and purchase.
Check balances, duplicates, missing fees and income classifications before filing Self Assessment.
Keep the full audit trail for at least five years after the 31 January filing deadline.
Further reading
If you want to learn more about this topic, these sources may interest you:
