Kraken Crypto Tax UK: How to Report Your Trades to HMRC (2025/26)

Kraken's data is unusually complete, yet Kraken users arrive at an accountant with the wrong numbers more often than most. The reason is the report people reach for first: a gain and loss summary computed the way the IRS wants it, not the way HMRC does. This guide covers the 2025/26 tax year (6 April 2025 to 5 April 2026, online filing deadline 31 January 2027) and the three Kraken-specific problems for UK users: the tax report's US methodology, the staking and rewards products, and derivatives. The click-by-click export steps are in the Kraken UK tax report guide; this post assumes you have the ledgers CSV.

Kraken's tax report is built for the IRS

Kraken's in-app tax documents and its partner tax exports compute gains on a lot-by-lot basis in US dollars, defaulting to FIFO. That is correct for a US filer and wrong for a UK one on three counts:

• Cost basis method. UK law (TCGA 1992 s.104) pools all units of the same token into a single Section 104 holding with an average cost. There are no lots. FIFO produces a different gain on almost every disposal where you bought at more than one price.
• Matching rules. Disposals are matched first to acquisitions on the same day (s.105), then to acquisitions in the following 30 days (s.106A), and only then to the pool. A US-format report has no 30-day rule; see the 30-day rule explained.
• Currency and tax year. The report is in USD over a calendar year. HMRC wants sterling, valued at the time of each transaction, across 6 April to 5 April.

The total on Kraken's summary is therefore not a number for any SA108 box, nor a reliable sanity check, since FIFO and pooling diverge most when prices moved a lot. Use the ledgers export instead, with the UK rules applied to it.

Reading the ledgers CSV

Every movement on Kraken is one row in the ledger; a trade is two rows (one asset out, one in) sharing a refid. The type column is what a UK computation keys off:

Asset codes use Kraken's internal names: XXBT is bitcoin, XETH is ether, ZGBP and ZUSD are fiat balances, and staked assets carry a suffix such as ETH2.S, DOT.S or SOL.S. The fee column is in the asset of the row; a fee in the outgoing asset reduces proceeds and a fee in the incoming asset increases cost (TCGA 1992 s.38, and the fees guide). Kraken lists GBP pairs for the major coins, so many UK trades are already in sterling; trades on USD or EUR pairs need a GBP value at the trade timestamp, not a monthly rate.

Staking and rewards: which products UK users actually had

Kraken's UK offering changed during 2025 as the FCA's financial promotion rules bedded in; UK retail clients now complete an appropriateness questionnaire and self-categorise before trading, and per Kraken's own restrictions list UK clients cannot use Opt-in Rewards, DeFi Earn or Kraken Drops. On-chain staking remains available in the UK for a restricted list of assets.

For 2025/26 that produces three points:

1. Every staking or earn credit is income. Each row of type staking or earn is miscellaneous income at its sterling value on the credit date, per CRYPTO21200. The amounts are net of Kraken's commission; report the net figure that landed. Total the year for SA100 box 17, unless your total miscellaneous income is under the £1,000 trading allowance. See staking rewards UK tax treatment.
2. Bonding and unbonding are not disposals. The ledger shows ETH leaving and ETH2.S arriving via transfer rows, and the reverse on unstake. Same asset, same owner. A tool that reads the ETH2.S row as a purchase and the ETH row as a sale will reset your pool cost to that day's price, which is wrong and usually expensive.
3. Rewards join the pool at their income value. Rewarded ETH enters your Section 104 ETH pool at the sterling value declared as income; selling it later is a second, CGT event on the movement since receipt.

Futures and margin: where the CGT and income line blurs

The FCA banned the sale of crypto derivatives to UK retail clients from 6 January 2021 (PS20/10). Kraken's derivatives run through Crypto Facilities Limited, an FCA-authorised firm, and Kraken's restrictions list states that UK retail clients cannot trade them; only elective professional clients can. A UK individual with 2025/26 futures activity therefore either opted up or was resident elsewhere at the time. Spot margin is more widely available and produces the margin, rollover and settled rows above.

HMRC has no bespoke perpetual futures guidance. The working position for an individual is:

• Each closed or settled contract is a disposal of the contractual rights, with the realised profit or loss converted to sterling at settlement. Kraken Futures settles in the collateral currency, so a profit in BTC is a BTC receipt and a loss in BTC is a BTC disposal, each valued in sterling on the day.
• The default is Capital Gains Tax. HMRC's published view (CRYPTO20250) is that an individual's crypto activity is investment unless the badges of trade are met, which is rare; the trader vs investor guide covers the test. If you are trading, everything including spot moves into Income Tax, so do not claim it casually to unlock loss relief.
• Funding payments and margin rollover fees are not incidental costs of acquisition or disposal under TCGA 1992 s.38, so they are not deductible against gains. Realised losses on contracts are allowable losses, usable against other gains or carried forward if claimed within four years.
• This is not spread betting. The exemption applies to bets with an FCA-authorised spread betting firm; a cash-settled futures contract is a derivative. The crypto spread betting guide explains the difference. The futures ledger is exported separately; both belong in the computation.

Section 104 pooling across Kraken and everywhere else

The pool is per token, per person, not per exchange. Your Kraken ETH, your Coinbase ETH and the ETH in a Ledger are one Section 104 pool with one average cost (TCGA 1992 s.104; HMRC CRYPTO22200). A Kraken-only report cannot be right if you have ever held the same token elsewhere: a sale on Kraken draws its cost from purchases made on Coinbase. For each disposal the order is same-day match, then 30-day match, then pool, applied across all venues in date order. The Section 104 pooling guide has the mechanics and a worked example.

Kraken-specific mistakes to check for

• Copying Kraken's gain figure to SA108. It is FIFO in USD on a calendar year. Discard it.
• Missing the earn rows. Rewards live in the ledger, not the trades export.
• Treating internal transfers as disposals. spottostaking, stakingfromspot and spottofutures rows are movements inside your own account.
• Stablecoin pairs. USDT/USD and USDT/GBP trades are disposals of the stablecoin, tiny per row and real in aggregate.
• Only exporting one year. A 2025/26 disposal draws its cost from purchases in 2019. Export everything from account opening.

Filing

Upload the full-history ledgers CSV, and the futures ledger if you have one, at cryptolens.uk/import; the parser recognises Kraken's asset codes and the .S suffixes and classifies each type above. Add any external wallet you withdrew to, so withdrawals reconcile as self-transfers rather than unexplained sends. Then review the Section 104 pools, the disposal list with the matching rule per line, and the miscellaneous income total at /tax before exporting the SA108 figures.

Kraken reports under CARF from 1 January 2026, so from 2027 HMRC receives your Kraken disposals and withdrawals directly; see the CARF guide.

This is general information, not personal tax advice.