UK Crypto Tax 2025/26 — The Practical Guide

The rates and allowances that matter in 2025/26

UK crypto tax in 2025/26 mostly runs through capital gains tax (CGT), with income tax applying for specific events (staking rewards, mining, airdrops received in certain ways, employment in crypto).

What counts as a disposal under HMRC's rules

HMRC's Cryptoassets Manual (CRYPTO22050) treats the following as a disposal for CGT purposes:

• Selling crypto for fiat (BTC → GBP, ETH → USD)
• Crypto-to-crypto swaps (BTC → ETH, ETH → USDC) — this catches almost everyone the first time
• Using crypto to pay for goods or services (paying for a coffee with BTC is a disposal)
• Gifting crypto to anyone other than a spouse / civil partner
• Donating crypto to charity (special rules apply — usually no gain, but check)

What is not a disposal:

• Buying crypto with fiat — acquisition only
• Moving crypto between your own wallets — no disposal; same beneficial owner
• Spousal transfers — no gain / no loss treatment, but the receiving spouse inherits the acquisition cost
• HODL — holding through volatility

The crypto-to-crypto rule is the biggest single source of unexpected UK tax bills. Most retail crypto users have many crypto-to-crypto trades and don't realise each one is a CGT event.

Share-pool matching — the s.104 pool and the 30-day rule

UK crypto follows the share-pooling rules from CG51550 with one exception we'll cover below. The matching order on a disposal:

1. Same-day rule — acquisitions of the same asset on the same day as the disposal pool together first.
2. 30-day "bed-and-breakfasting" rule — acquisitions in the 30 days after the disposal match next (this is the order HMRC actually applies — post-disposal acquisitions, not prior).
3. Section 104 pool — everything else pools together with an averaged cost basis.

What this means in practice for your wallet history:

If the August disposal matches a same-day acquisition (none here) and any 30-day post-disposal acquisitions, those would match first; only the residual matches the s.104 pool. Crypto tax software (Koinly, Recap, CryptoTaxCalculator, CoinTracking) handles this automatically — see our software comparison.

Income tax vs CGT — when each applies

Most crypto activity is taxed under CGT. Income tax applies in specific situations:

The double-tax pattern (income on receipt + CGT on disposal) is correct under UK rules and not double counting — the income-tax FMV becomes the CGT base cost, so only the appreciation after receipt is taxed under CGT.

What goes on your UK self-assessment return

For a typical UK crypto investor, the self-assessment touchpoints are:

• Capital Gains Summary (SA108) — total proceeds, total allowable costs, total gains, total losses, and the resulting taxable gain. Cryptoassets get their own line. You must file SA108 if your total proceeds (not gains) exceed 4× the annual exempt amount (£12,000 in 2025/26), OR if you have a chargeable gain above the AEA, OR you have losses you want to claim.
• Foreign pages (SA106) — if you hold crypto on foreign exchanges and need to report any foreign-tax credits, or if there are double-tax considerations.
• Other UK Income (SA100, box 17) — for staking, mining, airdrops, yield farming income taxed as miscellaneous income.
• Self-Employment Pages (SA103) — if you cross the line into commercial trader / commercial mining operation.

Required data per disposal:

• Date of disposal
• Asset disposed (token / coin name + chain if relevant)
• Quantity disposed
• Disposal proceeds (GBP at FX rate on date of disposal)
• Allowable cost (acquisition cost from s.104 pool + same-day + 30-day-rule matches)
• Resulting gain or loss

HMRC accept aggregated reporting on SA108 (total proceeds, total costs, total gain) rather than line-by-line — but you must retain the detailed records and produce them on request. Most crypto tax software produces a compliant SA108-ready summary.

HMRC nudge letters — what to do if you received one

HMRC has been sending "nudge letters" to UK crypto holders since 2019, with a noticeable uptick from 2023 onwards. The letters typically say HMRC has received information (usually from a UK or EU exchange) suggesting the recipient has held or traded crypto, and invite the recipient to check their tax position.

What to do if you receive one:

1. Don't ignore it. The letter is not an assessment, but ignoring it usually escalates to a formal enquiry.
2. Don't panic-amend. Get advice before amending past returns — there are right and wrong ways to disclose.
3. Reconcile your wallet history. Pull a full transaction history from each exchange + wallet you've used. Most crypto tax software can ingest CSV exports or read directly from exchange APIs.
4. Calculate any liability properly. Apply share-pooling, same-day, 30-day rules. Net gains and losses across the tax year.
5. If there's underpaid tax, use the Worldwide Disclosure Facility or a voluntary amendment. Voluntary disclosure attracts lower penalties (10-30%) than a discovery assessment after enquiry (30-100%).
6. Respond to the nudge letter with your position — either "I've reviewed and there's nothing further to declare" with the workings, or "I've reviewed and made a disclosure on date X under reference Y".

The exchanges sharing data with HMRC currently include Coinbase, Kraken, eToro, CEX.IO, Crypto.com, Binance (limited), Gemini, and most UK-regulated wallets. Once the EU DAC8 / OECD CARF framework lands in 2026-27, this data-sharing will widen dramatically.

The five most common UK crypto tax mistakes

1. Treating crypto-to-crypto swaps as not-a-disposal. Every swap is a CGT event. The most common cause of unexpected bills.
2. Mis-pooling — treating each acquisition separately rather than using the s.104 pool. Section 104 pools average the cost across all holdings; people use FIFO or LIFO instead, which is wrong under UK rules (it's right under US rules).
3. Ignoring the 30-day "bed and breakfasting" rule. If you sold and rebought the same crypto within 30 days, the post-disposal acquisition matches against the disposal at its actual cost, not via the pool. Often used incorrectly to engineer losses.
4. Treating staking rewards as not-income. Staking rewards are generally miscellaneous income at fair-market-value on receipt. The same FMV then becomes the CGT base cost for when you later dispose. Both events have tax consequences.
5. Not declaring because gains are below £3,000. The AEA covers gains up to £3,000, but if your proceeds exceed £12,000 you must still file SA108 with workings — even if the net gain after costs is below the AEA. Lots of people miss this.