How long do I need to wait to realise a loss against my pool?

Thirty-one days out of the asset. Rebuy on day 30 or earlier and the disposal matches your rebuy instead of your pool, and the pooled loss does not happen.

Do crypto-to-crypto swaps trigger the 30-day rule?

Yes. Every swap is an acquisition of the incoming token, so an active trader trips section 106A constantly without noticing.

The bed and breakfast rule catches the trade you were about to make

Every January somebody plans the same clever move. Sell the coins that are down, bank the loss against the year’s gains, buy the coins straight back, portfolio unchanged, tax bill smaller. The bed and breakfast rule exists specifically to stop this, and with crypto’s trading speed it catches far more people than it ever did with shares.

The rule. Dispose of a cryptoasset and buy the same asset back within 30 days, and the disposal is matched against the new purchase, not against your section 104 pool. The name comes from the old share trick of selling at close and rebuying at open, one night in the bed and breakfast. It sits in section 106A of the Taxation of Chargeable Gains Act 1992, applied to crypto through HMRC’s matching rules at CRYPTO22200.

The worked example, the one that hurts. Your ETH pool holds 10 ETH at £2,000 average. ETH trades at £1,400, so you sell 5 ETH for £7,000 expecting a £3,000 loss. Six days later you buy 5 ETH back at £1,450, costing £7,250. The rebuy is inside 30 days, so the disposal matches it, not the pool.

	Amount
Disposal proceeds	£7,000.00
Matched cost, the rebuy	£7,250.00
Result	£250.00 loss

The £3,000 loss you planned does not exist. You banked £250, and your pool of 10 ETH sits at £2,000 average exactly where it was. Realising the pooled loss would have taken 31 days out of the asset, and whether that market risk is worth the tax saving is a judgement, not arithmetic.

The order of matching, for completeness. Same-day purchases first under section 105, the following 30 days second, the pool last. Swaps count on both sides, a crypto-to-crypto trade is a disposal of one asset and an acquisition of the other, which is how active traders trip this rule weekly without noticing.

TaxHash applies the full matching order to every disposal on your own machine and labels each one with the rule that matched it and the law behind it, so a January plan can be checked before it becomes a January mistake. The complete UK guide covers all three rules with the current rates and allowances, and the app runs the real numbers on your real history, free below 1,000 transactions.