How much capital gains tax do I pay in the UK?

For disposals of shares, funds, and ETFs in 2026/27, taxable gains are generally charged at 18% to the extent they fall within the unused basic-rate band and 24% above it. The individual annual exempt amount is £3,000.

What is the capital gains tax allowance for 2026/27?

The individual annual exempt amount for the 2026/27 tax year is £3,000. It was £6,000 in 2023/24 and £12,300 in 2022/23.

How does the 30-day bed and breakfast rule work?

If you sell shares and repurchase shares of the same type within 30 days, the sale is matched with the subsequent purchase for CGT purposes. This anti-avoidance rule prevents investors from selling to realise a loss and immediately rebuying. FiscalFox applies this rule automatically.

Do I need to file SA108 for capital gains?

If you are registered for Self Assessment, you generally need to report gains when taxable gains exceed the annual exempt amount, when total disposal proceeds exceed £50,000 for 2023/24 onwards, or when you need to claim allowable losses or make another capital gains claim.

What does FiscalFox calculate for UK shares?

FiscalFox is a specialist UK capital gains tax calculator for share investors. It applies same-day matching, the 30-day bed and breakfast rule, and Section 104 pooling, then generates SA108-ready supporting reports. It has 13 built-in imports: Vanguard, Hargreaves Lansdown, Freetrade, Trading 212, eToro, InvestEngine, Moneybox, Saxo Bank, Interactive Brokers, Robinhood, Revolut, AJ Bell, and IG.

How do I report share sales to HMRC?

Share sales are reported on the SA108 supplementary pages of your Self Assessment tax return. You need to calculate the gain or loss on each disposal using HMRC's share matching rules, then enter the totals on SA108. The deadline is 31 January following the end of the tax year. FiscalFox can generate the SA108 schedules automatically from your broker export files.

Do I need to pay capital gains tax if my gains are under GBP 3,000?

If your total taxable gains are under the annual exempt amount, you do not owe CGT on those gains. If you are registered for Self Assessment, you may still need to report when total disposal proceeds exceed GBP 50,000 for 2023/24 onwards, or to claim allowable losses.

How do I calculate capital gains on shares?

Capital gains on shares are calculated as disposal proceeds minus allowable costs. HMRC requires same-day matching first, then acquisitions in the following 30 days, then Section 104 pooling. FiscalFox automates imported transaction matching and the current-year estimate. A brought-forward capital-loss balance must currently be applied separately.

What is the Section 104 pooling rule?

The Section 104 pool is a running average cost calculation for shares of the same type. When you buy shares, the cost is added to the pool. When you sell shares not matched by the same-day or 30-day rules, the cost is calculated as a proportion of the total pool cost based on the number of shares sold.

What are the current UK CGT rates?

From 30 October 2024: 18% for basic rate taxpayers and 24% for higher/additional rate taxpayers on shares and other assets. Before 30 October 2024: 10% and 20% respectively. Residential property has different rates.

What is the same-day rule for capital gains?

The same-day rule requires that if you sell shares and buy shares of the same type on the same day, the sale is matched with the same-day purchase for CGT purposes, regardless of the order of transactions during the day.

Can I carry forward capital losses?

Yes. If your capital losses exceed your capital gains in a tax year, you can carry forward the excess losses to offset against future capital gains indefinitely. You must report the losses to HMRC within 4 years of the end of the tax year in which they arose.

Is it really free to start?

Yes. Capital gains calculations are completely free, including calculations across multiple broker files. The one-time £29.99 payment is only needed to download the HMRC report pack, and unlocks the selected tax year plus earlier years in the calculation. There is no subscription.

Do you support my broker?

FiscalFox has 13 built-in broker imports: Vanguard, Hargreaves Lansdown, Freetrade, Trading 212, eToro, InvestEngine, Moneybox, Saxo Bank, Interactive Brokers, Robinhood, Revolut, AJ Bell, and IG. Other supported transaction files can use the opt-in AI import path after sign-in and consent.

Does FiscalFox apply HMRC share matching rules and protect data?

FiscalFox applies same-day, following-30-day and Section 104 matching in HMRC's prescribed order. Built-in broker parsing runs in the browser where possible; signed-in storage and opt-in AI parsing are described in the privacy policy. FiscalFox is a calculation tool, not tax advice or an HMRC submission.

When did CGT rates change in the UK?

The most recent change was on 30 October 2024, when the Autumn Budget increased CGT rates on shares from 10%/20% to 18%/24%. The annual exempt amount was reduced from £12,300 to £6,000 in April 2023, and further reduced to £3,000 in April 2024.

How do I know FiscalFox's calculations are correct?

FiscalFox applies the exact same share-matching rules HMRC uses to verify Self Assessment returns: same-day matching, 30-day bed and breakfast rules, and Section 104 pooling, in the correct priority order. Every disposal is traced and the calculations are defensible if you are ever questioned.

When do I need to pay for the report pack?

The free tier lets you calculate and view your capital gains on-screen. Pay £29.99 only when you want the downloadable HMRC-ready PDF and CSV report pack. The payment unlocks the selected tax year and every earlier year contained in the calculation.

Is there a subscription?

No. The report pack is a one-time £29.99 payment with no recurring charge. You can download the unlocked reports again whenever you need them.

What happens if my capital gains are wrong on my tax return?

If HMRC finds an error in your Self Assessment, you pay the extra tax plus interest, and a careless mistake can carry a penalty of up to 30% of the underpaid tax. Most DIY errors come from missing the same-day and 30-day matching rules. FiscalFox applies them automatically and keeps the workings behind every disposal so you can evidence your figures.

Which calculator is better for multiple broker accounts?

FiscalFox is designed to import supported files from multiple brokers into one calculation. CGTCalculator.com can accept manually prepared transaction text, which may suit investors willing to normalise their own data.

Which tool supports cryptoassets?

CGTCalculator.com advertises cryptocurrency calculations. FiscalFox is focused on shares, funds, ETFs and supported option transactions rather than cryptoassets.

Is either result a substitute for tax advice?

No. Both are calculation tools. Investors remain responsible for checking source data, unusual transactions and the figures submitted to HMRC.

FiscalFox vs CGTCalculator.com: UK CGT Tools Compared

Short answer: CGTCalculator.com is a strong free choice for manually prepared transactions, cryptoassets, older years and brought-forward losses. FiscalFox is the stronger workflow for supported broker exports, multi-broker share matching, review warnings and report evidence. The right choice depends on the data and the audit trail you need.

Feature comparison

Area	FiscalFox	CGTCalculator.com
Input	Native CSV or Excel imports for 13 named brokers; consented fallback parsing for an unrecognised layout.	Copy-and-paste transaction text and example formats; useful when the investor prepares the input.
Multiple brokers	Combines supported imports before matching the same security.	Possible through a combined manually prepared input.
Share matching	Same-day, following 30 days and Section 104 pooling, with disposal-level evidence and review warnings.	Calculates UK identification rules and provides a calculation result.
Asset focus	Shares, funds, ETFs and supported option rows. Not a crypto calculator.	Shares and cryptocurrency are advertised.
Brought-forward losses	Not currently entered or applied automatically.	Provides a carried-forward loss input.
Corporate actions	Detects or flags potential stock splits and other complex rows for review; it does not promise automatic treatment of every reorganisation.	Users can prepare adjusted transaction input; check the site guidance for the relevant event.
Outputs	Calculation preview plus paid PDF/CSV report packs and SA108 support fields for published filing years.	Free on-page calculation output.
Price	Free preview; prices are shown before purchasing a report.	Free to use.

When FiscalFox is the better fit

FiscalFox is built for the messy step before the tax calculation: interpreting broker exports, preserving source references, combining accounts, surfacing incomplete history and producing a reviewable disposal schedule. That is most valuable when there are many transactions or several brokers.

Try the UK capital gains tax calculator, read the calculation methodology, or inspect the synthetic report example before deciding.

When CGTCalculator.com is the better fit

If you want a free calculation, already have clean transaction text, need cryptoasset support, need a historical year outside FiscalFox’s range, or want to enter brought-forward losses directly, CGTCalculator.com may be the more suitable tool.

A precise note on data handling

FiscalFox parses supported broker files in the browser. Signed-in users can choose to save calculation data, and the interface asks before using an AI-assisted parser for an unrecognised file. Read the FiscalFox privacy policy for the complete terms. CGTCalculator.com states that uploaded data is not saved; read its privacy statement directly. Neither summary should replace the policy that applies when you use the service.

How this comparison was prepared

This page was checked against the public product interfaces and policies on 15 July 2026. It avoids ratings, invented customer counts and claims that cannot be reproduced. Product capabilities change, so verify a critical feature on the linked service before relying on it.

FiscalFox vs CGTCalculator.com

Feature comparison

When FiscalFox is the better fit

When CGTCalculator.com is the better fit

A precise note on data handling

How this comparison was prepared

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