Curve Finance Tax UK: CRV Rewards, Swaps and LPs

Curve is probably the trickiest protocol to get right for UK tax. Not because any single transaction is complicated (a stablecoin swap is straightforward enough) but because Curve touches so many different tax categories at once. Swaps, LP deposits, gauge staking, CRV rewards, veCRV locking, admin fee distributions. Each one has different tax treatment, and a single catch-all rule can lump them together incorrectly.

If you've been providing liquidity in 3pool, claiming CRV from the Minter contract, or locking CRV for boost, this is the breakdown of how HMRC treats each piece.

Curve swaps under current rules

Under the current rules, swapping DAI for USDC on Curve is a disposal of DAI and an acquisition of USDC, both valued at their GBP market price at the time of the transaction. The gain or loss is the difference between your Section 104 pool cost basis for the token you gave up and the GBP proceeds you received. Directly associated transaction gas can be an allowable cost under CRYPTO22150; unrelated or income-related fees should not be deducted from the gain automatically.

There's a practical quirk with Curve though. A huge portion of Curve's volume is stablecoin-to-stablecoin swaps. DAI to USDC. USDT to DAI. These are technically taxable disposals, but the actual gain is usually sub-penny, because you're swapping assets that are all pegged to roughly the same value. The gain (or loss) comes from minor FX fluctuations between USD stablecoins and the GBP exchange rate on that day.

For tax years before the announced reform, these disposals still need to be included when the applicable reporting tests are met. The total gain may be small, but it should be calculated rather than assumed.

Adding and removing liquidity under current rules

Under current HMRC guidance, depositing tokens into a Curve pool can dispose of those tokens in return for an LP interest (3Crv, steCRV, etc.). The result depends on the arrangement and whether beneficial ownership transfers. Where a disposal occurs, the LP interest is a new acquisition at the relevant GBP value.

Removing liquidity requires the reverse analysis: a disposal of the LP interest and acquisitions of the returned tokens can arise under the current rules.

Draft legislation published on 13 July 2026 proposes no-gain/no-loss treatment for qualifying automated market-making arrangements from 6 April 2027. It is not yet enacted, and using Curve does not by itself prove that every condition is met. See the DeFi NGNL explainer before applying that future treatment.

CRV gauge rewards are income, not capital gains

This is a common Curve classification trap. When you stake your LP tokens in a Curve gauge and claim CRV rewards via the Minter contract, those rewards are miscellaneous income, not capital gains. They're taxed at your income tax rate (20%, 40%, or 45%), and they go on the main SA100 tax return under "Other income," not on SA108 with your capital gains.

We classify Curve gauge rewards as income at fair market value on the date you claim them. The CRV tokens then enter your Section 104 pool at that same value, so if you later sell or swap the CRV, your cost basis is the income value you already reported.

For more on how staking and yield rewards work under HMRC rules, see our guide to reporting staking rewards.

veCRV locking: the grey area

Locking CRV for veCRV is genuinely ambiguous under current HMRC guidance. veCRV isn't transferable. You can't send it, sell it, or swap it. It's a non-transferable governance token that decays linearly over time. Does converting CRV into something non-transferable count as a disposal?

Arguably not. You haven't received a new asset with independent economic value. veCRV only exists to boost your gauge rewards and vote on pool weights. It's more like staking than swapping. ChainTax classifies the CRV → veCRV lock as a transfer (non-taxable), which is the conservative position most accountants we've spoken with prefer.

If HMRC ever clarifies this, we'll update. For now, the safe approach is treating the lock as non-taxable and keeping your CRV cost basis intact for when the lock eventually expires.

Admin fees from veCRV

veCRV holders receive a share of trading fees from Curve pools, paid in 3Crv. These are income, with the same treatment as CRV gauge rewards. Miscellaneous income, valued at FMV on receipt, taxed at your income tax rate. The 3Crv tokens enter your S104 pool at that value.

Gauge boosts and the boost multiplier

The gauge boost system (up to 2.5x rewards based on your veCRV balance relative to your LP stake) doesn't create a separate tax event. It just means you earn more CRV per block. The tax treatment is identical: it's all income when claimed. A boosted reward and an unboosted reward are taxed the same way; there's just more of it.

Curve LP tokens and Section 104

3Crv, steCRV, crvFRAX are all real tokens with market prices. They enter your Section 104 pool when you acquire them and leave it when you dispose of them. If you add liquidity three times over six months, all three deposits merge into a single pool with a weighted average cost basis. When you remove liquidity, units come out of that pool.

One thing worth noting: if the pool's value has changed between deposit and withdrawal (due to fees earned, impermanent loss, or token price movement), that difference shows up as a capital gain or loss on the LP token disposal. The LP token's S104 cost basis reflects what you paid to acquire it, not what the underlying tokens are currently worth.

Common mistakes with Curve tax

In practice, most Curve users we've seen make one or more of these errors:

• Treating CRV rewards as capital gains. This is the big one. Wrong tax rate, wrong form, wrong reporting location.
• Ignoring stablecoin swaps. Yes, swapping DAI for USDC is a disposal even though the gain is tiny. Missing hundreds of these can trigger HMRC questions about unreported disposals.
• Not tracking LP token cost basis. The LP token you received when depositing has a cost basis. If you don't track it, your withdrawal gain calculation will be wrong. A UK crypto tax calculator built for DeFi keeps the LP-token pool separate from the underlying pair so the maths stays straight.
• Double-counting gauge deposits. Staking LP tokens in a gauge isn't a disposal. You're depositing them into a staking contract, not exchanging them for something new. Some tools create phantom events here.

How ChainTax classifies Curve transactions

Our classification engine recognises Curve's on-chain contracts across Ethereum mainnet: pool swaps, the Minter contract for CRV claims, gauge deposits and withdrawals, and LP token minting/burning. Each transaction type maps to the correct HMRC category:

• Pool swaps → Capital gain (disposal at market value)
• CRV rewards via Minter → Income (miscellaneous, FMV on receipt)
• LP deposits/withdrawals → Capital gain (disposal of tokens in, acquisition of LP token out, or vice versa)
• veCRV locking → Transfer (non-taxable)
• Admin fee distributions → Income

Where Curve activity goes on your tax return

Capital gains from swaps and LP disposals go on SA108, the capital gains supplementary page. For 2024/25, HMRC added dedicated crypto boxes (13.1–13.8) so your Curve swap gains slot in alongside all your other crypto disposals.

CRV rewards and admin fee income go on SA100, the main tax return, under "Other income." This is where all DeFi yield, staking rewards, and miscellaneous crypto income belongs. Keeping these separate is essential, because mixing capital gains and income on the wrong forms is exactly the kind of error that triggers HMRC enquiries.

Get your Curve tax right

Curve rewards, LP positions, and stablecoin swaps all need correct classification to avoid overpaying or misreporting. ChainTax classifies supported Curve swaps, liquidity actions, gauge claims, and veCRV locks; incomplete or unfamiliar activity remains visible for review.

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