Short answer: UKCGT is a capable free calculator. It applies the same-day, 30-day and Section 104 rules, reads CSV files from several UK brokers at once and runs in your browser. If you have ordinary share and fund trades at brokers it reads, it may be all you need. FiscalFox is a paid report built for the harder cases: more brokers, US shares and share plans, corporate actions, options, automatic ERI, a tax figure after your allowance, and a report pack an accountant can check.
Checked on 12 October 2026 against ukcgt.xyz (the calculator page, its How It Works page, broker formats page and ERI Lookup page). Free tools change often, so check the site for anything that matters to you.
FiscalFox vs UKCGT at a glance
| Area | FiscalFox | UKCGT (ukcgt.xyz) |
|---|---|---|
| Price | Calculation preview is free. Report pack £39.99 per tax year, paid once. Optional done-for-you report £100. | The calculator page shows no price, sign-up or payment step. |
| Share matching | Same-day, following 30 days, then the Section 104 holding, across all imported accounts. | Same-day, 30-day bed and breakfast, then Section 104 pooling. |
| Broker files | 18 built-in imports, including Trading 212, Freetrade, Interactive Brokers, Interactive Investor, Hargreaves Lansdown, AJ Bell, Vanguard, Charles Schwab and Robinhood, plus an AI import for other layouts. | CSV files from Trading 212, Freetrade, Barclays (saved as CSV first), Interactive Brokers (GBP base currency), Interactive Investor, Hargreaves Lansdown, Lightyear/Sharesight and AJ Bell, plus cgtcalculator.com text. Several files can be loaded together. |
| Foreign currency | Converts non-sterling trades at the Bank of England daily rate for each date (European Central Bank rate as a backup) and shows the rate used. | Looks up historical rates from Frankfurter for non-GBP rows in Interactive Investor and Trading 212 files. |
| ERI on offshore funds | Spots reporting funds from the ISINs in your export and adds published ERI to the pool cost automatically for funds it holds figures for. A missing figure is not treated as zero. | A separate ERI Lookup tool finds published ERI for the funds you held; you paste its lines into the calculator to add them to the pool cost. |
| Corporate actions and options | Researches splits, consolidations, spin-offs, mergers and share class changes against published sources, checks them against your holdings and asks you to review anything it cannot confirm. Reads supported option rows. | Its notes say reorganisations and options are not included. |
| RSUs and ESPP | Reads Charles Schwab brokerage and Equity Awards history, and Morgan Stanley StockPlan Connect exports. | Schwab and Morgan Stanley are not among the formats it lists. |
| Tax due | Applies the annual exempt amount, losses you bring forward and the CGT rates to estimate the tax due. | Its notes say it does not apply a tax rate, the annual exemption or loss carry-forward. |
| Output | On-screen workings free. Paid PDF and CSV report pack with every disposal, Section 104 pool workings, SA108 figures for published filing years and Self Assessment working papers. | Tax-year summary, disposal-by-disposal calculations and current Section 104 holdings, with buttons to save an HMRC report, the trades and the holdings as CSV. |
| Your data | Built-in imports are read in your browser where possible. Saving work needs an account, and some features (the AI import and corporate action research) send data to AI providers, as the privacy policy explains. | States that processing runs in your browser and trade data does not leave your device, apart from the currency lookups and an optional ticker conversion helper. |
What UKCGT does well
UKCGT reads the raw CSV files from the brokers it supports, so you do not need to retype trades. You can select files from several brokers in one go and it combines them into one calculation, which is exactly what UK share matching needs. It says it removes duplicate Trading 212 and Interactive Investor rows by their broker reference and warns you about identical trades.
It shows its workings: a summary for each tax year, the calculation for each disposal and your Section 104 holdings. It also says its results should be similar to cgtcalculator.com with rounding turned off, which gives you a second free tool to check against. And it runs in your browser, which some people rightly value.
When UKCGT is probably enough
- All your taxable trades are at brokers in its list, for example a single Trading 212 Invest account.
- You trade ordinary shares, ETFs or funds, with no options, no share plans and no reorganisations.
- You are happy to apply the £3,000 annual exempt amount, any losses you bring forward and your tax rate yourself.
- If you hold accumulation ETFs, you are comfortable using its ERI Lookup tool and pasting the results in.
In that situation a free tool is a reasonable choice, and you may not need to pay for anything.
When FiscalFox is worth paying for
- Brokers outside its list: for example Vanguard, eToro, InvestEngine, Robinhood, Revolut, Saxo, IG or Webull. See the supported brokers.
- US shares and share plans: Schwab RSU vests, ESPP purchases and sell-to-cover sales. See the RSU and ESPP guide.
- Corporate actions: splits, spin-offs, mergers and share class changes that alter your pool. See stock splits and corporate actions.
- Options from supported brokers, and crypto gains imported from a Koinly Capital Gains Report into the same report.
- An answer, not just a gain: the estimated tax after your allowance and losses, and the figures for the SA108 boxes.
- Workings someone else will check: a report pack with every disposal and pool movement that an accountant can follow.
- A file that will not import: the done-for-you service prepares your report for £100 within 2 working days, with a full refund if it cannot be done or is late.
Using both as a check
You do not have to choose. Run your full history through UKCGT and through the free FiscalFox calculation. If the gains agree, that is good evidence your data is complete. If they differ, look at the disposals that differ: a missing file, a corporate action, a currency conversion or ERI is the usual cause. Read the FiscalFox methodology to see how each rule is applied.
About this comparison
This comparison is not a claim that UKCGT is inaccurate. It sets out what each tool documents on its own website on the date checked. FiscalFox is independent and is not affiliated with, endorsed by or sponsored by UKCGT. Neither tool gives tax advice; check unusual transactions with a qualified adviser.
Frequently asked questions
Is UKCGT good enough for my capital gains tax?
Often, yes. UKCGT applies the same-day, 30-day and Section 104 rules, combines several broker CSV files and runs in your browser. If your trades are ordinary buys and sells of shares or funds at brokers it reads, with no reorganisations or options, it may be all you need. You then apply the annual exempt amount, any losses brought forward and your tax rate yourself.
What does FiscalFox do that UKCGT does not?
Going by what each site documents: FiscalFox works out the estimated tax after the annual exempt amount and your rate, applies losses you bring forward, handles supported option rows, researches corporate actions such as splits and spin-offs, reads Charles Schwab RSU and ESPP history, adds published ERI to fund costs automatically for funds it holds figures for, and produces a report pack with SA108 figures. The report pack costs £39.99 per tax year; the calculation preview is free.
Does UKCGT handle ERI on accumulation ETFs?
It has a separate ERI Lookup tool. That tool checks HMRC's list of reporting funds, looks up published ERI for the funds you held, and gives you lines to paste into the calculator so the ERI is added to your pool cost. FiscalFox does this step automatically for funds whose published figures it holds, and does not treat a missing figure as zero.
Can I check one tool against the other?
Yes, and it is a sensible thing to do. Run the same complete broker history through both. If the disposal gains differ, compare the matching for the disposals that differ: the usual causes are a missing file, a corporate action, a currency conversion or ERI.
Official 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.