Question 1

How do I calculate UK Capital Gains Tax on shares?

Accepted Answer

To calculate UK CGT on shares, you need to apply HMRC's share matching rules in order: same-day rule (match sales with same-day purchases), 30-day bed and breakfast rule (match with purchases within 30 days after sale), then Section 104 pool (average cost of remaining shares). TaxBull automates this entire process from your broker CSV export.

Question 2

What is the Capital Gains Tax allowance for 2025/26?

Accepted Answer

The Capital Gains Tax annual exempt amount for 2025/26 is £3,000 per individual. This was reduced from £6,000 in 2023/24. You only pay CGT on gains above this threshold.

Question 3

What are the UK CGT rates for shares in 2025/26?

Accepted Answer

From 30 October 2024, CGT rates on shares and other assets are 18% for basic rate taxpayers and 24% for higher and additional rate taxpayers. Previously the rates were 10% and 20%.

Question 4

How do I report Capital Gains Tax on my self-assessment?

Accepted Answer

Capital gains from shares are reported on the SA108 Capital Gains Summary supplementary page. Listed shares go in Boxes 23-30 and options or other assets in Boxes 14-22. TaxBull maps your gains directly to these SA108 boxes.

Question 5

What brokers does TaxBull support?

Accepted Answer

TaxBull supports CSV imports from Robinhood UK (stocks, options, assignments), Tastytrade (stocks and options), Trading 212 (stocks and ETFs), Freetrade (GIA orders), and any broker via the generic CSV format.

Question 6

What is the Section 104 share pool?

Accepted Answer

The Section 104 pool (or share pool) groups all shares of the same class in the same company into a single pool with an average cost per share. When you sell, the cost is calculated using this average. Same-day and 30-day matching rules take priority over the pool.

Question 7

How are options taxed for UK Capital Gains Tax?

Accepted Answer

Options are treated as chargeable assets under HMRC rules. Gains or losses are realised when positions are closed (BTC/STC), expire worthless, or are exercised/assigned. The premium paid or received forms part of the cost basis or disposal proceeds.

Question 8

What exchange rate should I use for foreign shares?

Accepted Answer

HMRC requires you to use their published monthly exchange rates to convert foreign currency transactions to GBP. These rates are published at trade-tariff.service.gov.uk. TaxBull uses these official HMRC rates automatically.