Section 104 pooling for shares and crypto

What goes into a Section 104 pool?

For an individual holding investments in the same capacity, shares of the same class in the same company normally share a pool. Each type of fungible crypto token has its own pool. Separately identifiable assets such as NFTs are outside this pooling treatment.

The pool records a quantity and a total allowable cost. Average cost is total pool cost divided by units held. It is a record of acquisition cost, not the investment’s current market value.

Check same-day and 30-day matching first

A disposal is matched first to acquisitions on the same day, then to qualifying acquisitions in the following 30 days. Only the remaining units use the pool. These examples assume no such acquisitions, no other transactions and no fees.

Example: selling part of a shareholding

You buy 100 shares at £10 and a further 100 at £20. Together they form a pool of 200 shares costing £3,000. You later sell 50 shares at £25 each.

Average cost

£3,000 ÷ 200 = £15 per share

Sale proceeds

50 × £25 = £1,250

Allowable cost

50 × £15 = £750

Capital gain

£1,250 − £750 = £500

Remaining pool

150 shares costing £2,250

A later purchase changes the average

After that sale and outside its 30-day window, you buy 50 more shares at £30. Adding £1,500 to the remaining £2,250 gives a pool cost of £3,750 for 200 shares. The new average is £18.75. The earlier sale’s £500 gain stays the same under these assumptions.

You cannot pick the most expensive purchase to set the cost of the next sale. The identification rules determine which acquisitions supply the allowable cost.

Example: a partial crypto disposal

Suppose you hold 2 tokens with a combined allowable cost of £4,000. Selling 0.5 tokens for £1,500 uses one quarter of the pool’s cost: £1,000. The gain is £500, and the remaining 1.5 tokens have a pool cost of £3,000. These are illustrative prices, not market quotes.

Keep records across wallets and exchanges for the same token. A platform’s balance alone does not establish your total pooled allowable cost.

Reviewing pools in Gainly

Import the history that establishes each asset’s cost, then review the matched disposals on Gains. Home shows current pool units, cost and average cost. Changing the tax year updates the CGT position; it does not turn Holdings into a historical snapshot.

The gains above are before losses and the annual exemption. They are not amounts of tax payable. Unusual acquisitions, corporate actions or incomplete records may need separate advice.