UK Capital Gains Tax Guide

A plain-English guide to CGT for UK self-directed investors. Click any topic below to read the full guide with worked examples.

Last updated: April 2026

What is a Section 104 Pool?

How HMRC pools your share purchases into a single cost basis — with worked examples.

Sold and rebought within 30 days? This anti-avoidance rule changes how your gain is calculated.

Current rates, annual exempt amounts, and the October 2024 Budget changes explained.

Step-by-step walkthrough of the HMRC SA108 supplementary page for capital gains from shares.

How to export your Trading 212 transaction history and calculate your capital gains tax.

Export your HL transactions and handle the pence-to-pounds quirk automatically.

Step-by-step guide to exporting your Freetrade CSV and calculating CGT correctly.

Upload your broker CSV and get your exact tax position in minutes.

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