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.

Does FiscalFox support IG share dealing transaction history?

Yes. FiscalFox has a deterministic parser for native IG TradeHistory CSV and TransactionHistory Excel exports from taxable Share Dealing accounts.

How do I download an IG transaction history report?

In My IG, go to Live Accounts, choose the taxable Share Dealing account, open History and Transactions, set Type to All, choose a Custom Period, select Show History, and download the CSV.

Can I upload an IG CFD or spread-betting history?

No. The IG importer is limited to settled share dealing. CFD, spread-betting, derivative, leveraged, unsettled, or unreconciled activity blocks the file so it cannot be mistaken for ordinary shares.

Why did FiscalFox reject my IG file?

FiscalFox rejects the complete file if it finds an unsettled trade, a leveraged or derivative row, an unmatched fee, an unreconciled total, a malformed row, or a dividend reversal that needs manual reconciliation.

IG Capital Gains Tax Calculator UK

FiscalFox supports native transaction-history exports from taxable IG Share Dealing accounts. It imports settled share purchases and sales, converts foreign trades using the exchange rate in the file, attaches commission and SDRT, and applies the UK same-day, 30-day, and Section 104 matching rules. It deliberately rejects CFDs, spread bets, unsettled trades, and files whose cash values do not reconcile.

How to generate the IG transaction history report

IG's current help guidance places the export under My IG Dashboard. Use the taxable Share Dealing account that contains the disposals you are calculating. An ISA history is normally outside UK CGT, while CFD and spread-betting histories represent different products and are not accepted by this importer.

Open the taxable account: Sign in to My IG, open Live Accounts, and select the taxable Share Dealing account rather than an ISA, CFD, or spread-betting account.
Open transaction history: Choose History and then Transactions.
Select the complete period: Set Type to All, choose Custom Period, and include the earliest relevant purchase through the end of the tax year.
Download the native file: Select Show History and download the original CSV without renaming columns or converting it into a custom spreadsheet.
Upload to FiscalFox: Choose IG in FiscalFox and upload the native TradeHistory CSV. Legacy native TransactionHistory XLS or XLSX exports are also accepted.

You can compare these steps with IG's official financial-year transaction history instructions. IG describes the route as Live Accounts, History, Transactions, with Type set to All and a Custom Period before selecting Show History.

Export enough history to rebuild the share pool

A tax-year-only file may omit older acquisitions that still form part of a Section 104 pool. Start from the earliest relevant purchase or upload consecutive native exports that together cover the complete holding history.

Which IG files are supported?

FiscalFox recognises two native IG layouts:

TradeHistory CSV with fields including Activity, Market, Direction, Quantity, Consideration, Commission, Charges, Cost/Proceeds, Conversion rate, Settled?, and Order ID.
TransactionHistory XLS/XLSX with ledger rows such as Client Consideration, Share Dealing Commissions, SDRT, cash movements, and dividends.

Custom spreadsheets with renamed columns are not accepted under the IG option. Keeping the broker's original headers gives the parser the evidence it needs to distinguish a settled equity trade from a cash movement or leveraged product.

How FiscalFox validates IG trades

Check	Result
Settlement status	Every imported TradeHistory row must be settled
Trade economics	Consideration, FX, commission, charges, and cost/proceeds must reconcile
Ledger fees	Commission and SDRT must match a specific consideration row
Product guard	CFD, spread-betting, derivative, and leveraged signals block the file

Why IG imports fail closed

FiscalFox uses an all-or-nothing import for IG. If one row is unsettled or cannot be reconciled, none of the file's rows are saved. This avoids producing a plausible-looking tax calculation from an incomplete subset. Re-export after trades have settled, and contact support if an unchanged native export still fails.

Dividend reversals and negative adjustments also block the file because they can represent corrections that must be paired before gross income and withholding are reported. Positive dividends from a clean native ledger can be imported, but country classification should still be reviewed when IG does not provide an ISIN or issuing country.

Calculate and download your report

Open the FiscalFox calculator and choose IG.
Upload the unchanged native file and review the imported transactions.
Select the relevant UK tax year and check any security-resolution or opening-position prompts.
Review the calculation, then open the Reports tab to generate the SA108 supporting schedule and detailed disposal workings.