One of the most common misunderstandings among new crypto investors is thinking that tax only becomes relevant once you convert crypto back into pounds. That is not how HMRC sees it, and the swap itself is usually the moment that matters.
The Short Answer
Yes. Swapping one cryptocurrency for another, for example trading Bitcoin for Ethereum, is treated by HMRC as a disposal of the first asset. This is true even though no pounds ever touch your bank account. If the value of the crypto you are giving up has increased since you acquired it, that increase can be a taxable capital gain at the moment of the swap.
Why HMRC Treats Crypto This Way
HMRC classifies cryptoassets as property rather than currency. Under general Capital Gains Tax principles, disposing of an asset, whether by selling it, swapping it, spending it, or gifting it, is a taxable event if there is a gain. A crypto-to-crypto swap fits squarely into that definition because you are giving up one asset and receiving a different one in return. You can read HMRC’s own position directly in the HMRC Cryptoassets Manual.
Working Out the Gain on a Swap
The calculation follows the same basic method as any other disposal:
- Work out the GBP value of the crypto you received at the moment of the swap. This becomes your disposal proceeds for the asset you gave up.
- Subtract the cost basis of the asset you gave up, meaning what you originally paid for it in GBP, plus any allowable transaction fees.
- The result is your gain or loss on that specific disposal.
The crypto you receive then has its own new cost basis, equal to its GBP value at the point you acquired it through the swap. That value carries forward and matters again the next time you dispose of it.
A Worked Example
Suppose you bought 1 ETH for £1,500. Later, when 1 ETH is worth £2,200, you swap it for a different token. You have disposed of the ETH for £2,200 in value, giving a gain of £700, even though you never converted anything to GBP. The new token you received now has a cost basis of £2,200 for when you eventually sell or swap it again.
Does the Tax-Free Allowance Help?
Individuals have an annual Capital Gains Tax exempt amount that applies to total gains across all assets in a tax year, not just crypto. If your total gains for the year, including gains from swaps, stay within that allowance, you may owe no Capital Gains Tax. Frequent swapping across many small positions can add up faster than people expect, so tracking each disposal matters even if individual gains look small.
What About Swaps Inside DeFi Protocols?
Swapping tokens through a decentralised exchange works the same way for tax purposes as swapping on a centralised platform. Each swap is still a disposal of the token you put in. This applies whether you are trading directly through a protocol’s interface or through a wallet connected to one, which we cover in our crypto wallets guide and our overview of how DeFi works.
Practical Record-Keeping
Because every swap is a separate disposal, active traders can end up with dozens or hundreds of taxable events in a single year. For each swap, keep a record of the date, the assets involved, the GBP value at the time, and any fees paid. Our trading and investing guide covers broader record-keeping habits worth building early.
Frequently Asked Questions
Does this apply to stablecoin swaps too?
Yes. Swapping a volatile coin for a stablecoin is still a disposal of the volatile coin, and any gain since you acquired it is potentially taxable, even though the stablecoin’s value barely moves.
What if the swap results in a loss?
A loss on a swap can usually be used to offset gains elsewhere in the same tax year, or carried forward, provided it is reported to HMRC. HMRC’s guidance on record keeping for cryptoassets is available in CRYPTO10400. Keeping records of losing trades matters just as much as recording gains.
Is this different from swapping crypto for an NFT?
The same general disposal principle applies. Using crypto to acquire an NFT is a disposal of that crypto, valued at the GBP price of the NFT at the time.
This article explains general HMRC principles and is not personalised tax advice. Crypto tax rules and allowances can change, so confirm current rates and thresholds with HMRC or a qualified accountant before filing.
