Start with the current-year guide if you need rates and allowances, or use the share-matching guides when you need to understand how a disposal is connected to earlier and later purchases. The broker guides cover the separate practical question of which transaction file to export.
FiscalFox organises its guidance around the sequence used in a UK share calculation: establish the taxable account history, identify the same security across accounts, apply same-day and following-30-day matching, then update the Section 104 holding. Reporting guides explain how the resulting totals can support Self Assessment without presenting the calculator as an HMRC filing service or personal tax advice.
Rate, allowance and matching-rule statements link to GOV.UK or HMRC material, including Helpsheet 284 and the current Capital Gains Tax rates. Each detailed guide states its publication and update dates so readers can distinguish current-year figures from enduring calculation principles.
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Open calculatorCGT basics
Rates, allowances, reporting thresholds, and examples.
Read guideStep-by-step share disposal calculations.
Read guideCurrent rates, allowances and reporting context.
Read guideHow the £3,000 annual exempt amount works.
Read guide2026/27 rates and the historical split-year change.
Read guideHMRC share matching rules
How same-day purchases are matched.
Read guideThe anti-avoidance rule for quick repurchases.
Read guideAverage cost pooling for remaining shares.
Read guideUsing, claiming, and carrying forward losses.
Read guideNo-gain/no-loss transfers and inherited pooled cost.
Read guideHow reorganisations affect quantities and pooled costs.
Read guideReporting and SA108
What goes into the Self Assessment capital gains pages.
Read guideHow excess reportable income affects taxable accounts.
Read guideBroker workflows
Find the right export instructions for your platform.
Read guideCombine matching securities across investment accounts.
Read guideRecords, supported scope and complex cases.
Read guideCompare portfolio tracking with a specialist UK CGT workflow.
Read guideOfficial UK tax references
This guide is checked against published GOV.UK and HMRC material. FiscalFox is a calculation tool, not personal tax advice; review unusual transactions with a qualified adviser.