A larger Capital Gains Tax bill can arise when you sell BTC, swap it or transfer it to your spouse because HMRC treats each action differently.
Bitcoin has no blanket UK tax exemption, but costs, losses, the annual CGT exempt amount and qualifying spouse transfers may reduce the bill.
Which bitcoin actions trigger UK tax?
For an England tax resident, Capital Gains Tax usually starts when you dispose of Bitcoin, meaning you give up ownership for cash, another asset, goods, services or a gift. HMRC treats Bitcoin as a cryptoasset, and its Cryptoassets Manual sets out this approach.
| BTC action | CGT disposal? | Value used | Main exception or issue |
|---|
| Buy and hold BTC | No | Not applicable | No taxable gain exists until disposal |
| Move BTC between own wallets | Normally no | Not applicable | You must keep beneficial ownership |
| Sell BTC for GBP | Yes | GBP sale proceeds | Costs, losses and annual exemption may reduce gain |
| Swap BTC for crypto | Yes | GBP market value | No cash receipt is needed |
| Gift BTC to spouse | Usually no | Original base cost carries over | Must be married or in a civil partnership and living together |
| Gift BTC to friend | Yes | GBP market value | A gift is still a disposal |
Holding BTC creates no CGT charge because there has been no disposal. Moving BTC between accounts you own is normally outside CGT if you retain beneficial ownership and control.
Sales, swaps and bitcoin spending
Selling BTC for GBP, exchanging it for another token, or buying goods with it normally creates a gain or loss. Use the sterling value at the time of the transaction, less allowable disposal costs.
Which reliefs can reduce a bitcoin gain?
Calculate the gain using the correct matched cost, deduct allowable costs, offset allowable capital losses, then apply the Annual Exempt Amount. For 2026/27, this is £3,000 across your total net capital gains, not each BTC transaction.
A £4,200 net Bitcoin gain does not automatically create tax on £4,200. If you have no other capital gains or losses, the £3,000 Annual Exempt Amount leaves £1,200 potentially taxable. If you used the allowance on a share sale, it may leave nothing for BTC.
Costs that reduce the gain
Allowable costs can include BTC purchase cost, exchange trading fees, blockchain fees directly tied to acquiring or disposing of BTC, and necessary valuation costs. Keep every figure in GBP.
Capital losses and HMRC deadlines
An allowable BTC loss can reduce gains in the same tax year, and unused losses can normally carry forward. You must claim the loss, generally within four years after the relevant tax year ends.
Income events are not CGT reliefs
Mining, staking rewards, some airdrops and business income in Bitcoin may fall under Income Tax when received. Income Tax paid can help establish acquisition value for a later CGT calculation.
How BTC matching rules set taxable gains
The same-day rule, 30-day rule and Section 104 holding decide which BTC cost is matched against a disposal, and HMRC applies them in that order.
For example, if you sell 0.10 BTC on 10 June for £6,000 and buy 0.10 BTC on 20 June for £5,500, the later purchase falls within 30 days. The £5,500 cost is matched to the sale, producing a £500 gain before fees.
Same-day matching comes first
BTC acquired and disposed of on the same UK tax date is matched first. Save trade times, platform statements and GBP values because exchange timestamps can use different time zones.
The section 104 pool follows
After same-day and 30-day matches, the disposal comes from your Section 104 holding, a pooled average cost. If you hold 1 BTC costing £20,000 and add 1 BTC costing £40,000, the pooled average is £30,000 per BTC.
Build an HMRC-ready evidence file
Your records should link every disposal to a clear evidence trail, as HMRC can request records and reporting from cryptoasset providers is expanding.
- Keep the date and time, BTC quantity, GBP market value, fee and platform for each trade.
- Keep wallet addresses, transaction hashes and transfer notes showing that two wallets were both yours.
- Keep spouse or civil-partner transfer evidence, including the transfer date and proof that you were living together.
- Keep charity confirmation showing that the recipient was an eligible charity and the BTC was donated directly.
- File Self Assessment by 31 January after the tax year ends, and register by 5 October where required if this is your first return.
This guide is not a substitute for individual advice if you are not UK tax resident, trade professionally, receive BTC through work or business, use a company, use DeFi or derivatives, or have lost BTC through fraud, a hack or missing keys. No CGT relief is needed where you only hold BTC or move it between wallets you own and make no other disposal.
Your questions answered
Can I cash out bitcoin tax-free in the UK?
There is no fixed tax-free cash-out amount. CGT depends on total gains, losses, costs and the £3,000 Annual Exempt Amount.
Can I claim crypto losses on my UK taxes?
Yes, if the loss comes from an allowable disposal and you claim it with HMRC. Unused allowable losses can normally carry forward.
Is swapping BTC for another crypto taxable?
Yes, a BTC-to-crypto swap is normally a CGT disposal at the BTC sterling market value at that time.
Can I give bitcoin to my spouse without tax?
Usually, yes, if you are married or in a civil partnership and living together during the tax year. Your spouse takes your existing allowable cost.
Is donating bitcoin to charity tax-free?
A direct donation to an eligible charity can receive different CGT treatment from a gift to a friend or family member. Retain the donation confirmation.
Can HMRC see my bitcoin transactions?
HMRC can obtain information from UK and overseas cryptoasset providers and compare it with your Self Assessment return.
