🇬🇧 UK Capital Gains Tax.
Calculated Correctly.

The Museum (Free) tier is completely free — no credit card needed. Just sign in with Google or a magic link, upload your broker CSV, and get an HMRC-compliant CGT summary for up to 10 stock disposals. The Fish & Chips (Investor) tier is £12.95/year and unlocks the full per-trade report, PDF export, options trading, fund reporting, and unlimited disposals.

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On the Museum (Free) plan your data is processed on our server and never stored. On the Fish & Chips (Investor) plan all calculations run entirely on your own device — nothing is sent to the server.

When you sell shares, HMRC requires a specific order to determine which shares you sold (CG51560). First, the Same Day Rule matches any shares bought on the same day as the sale. Second, the Bed & Breakfast Rule matches shares bought within the next 30 days. Third, remaining shares come from your Section 104 Pool, a running average cost basis of all prior acquisitions.

Example: you sell 100 AAPL on 15 March. If you bought 100 AAPL that same day, those match under Same Day. If not, any AAPL purchase between 16 March and 14 April matches under Bed & Breakfast. Everything else uses your Section 104 average cost.

Under HMRC rules (CG12300), each option contract is a separate chargeable asset — options are not pooled like shares. When you sell to close an option, the gain or loss is the difference between closing and opening premiums. When you write (sell to open) an option, the premium received is a disposal under CG12312 and CG55590.

If the option expires worthless, the writer keeps the full premium as a gain and the buyer claims a capital loss. CGT Calculator tracks all of these outcomes automatically for 60+ strategies.

An iron condor has four legs, each taxed as a separate CGT asset per CG12300 and CG55590. Example: sell a 95 put for £200 premium, buy a 90 put for £50, sell a 110 call for £180, buy a 115 call for £40. Net credit: £290.

If all options expire worthless, you have four disposals — two gains from written options (£200 and £180) and two losses from bought options (£50 and £40). Net gain: £290 converted at the relevant GBP/USD rate on each transaction date.

Per CG12300, when a call option is exercised, the option premium adjusts the stock cost basis. If you bought a call with a £150 strike for £1.20/share premium, your acquisition cost for the stock is £150 + £1.20 = £151.20/share, plus fees.

For put options, exercising means selling stock at the strike price, and the premium paid reduces your disposal proceeds. When assigned on a written option, the premium received adjusts the stock transaction similarly.

Nine brokers and exchanges: Interactive Brokers (IBKR), Charles Schwab, Trading 212, Freetrade, Morgan Stanley, Revolut, Robinhood, Binance, and Coinbase (last three in beta). Covers stocks, options, and cryptocurrency. Each requires a specific CSV or Excel export — upload from multiple sources and get a single HMRC-compliant report.

See the Documentation for step-by-step export instructions.

HMRC treats cryptocurrency as property, not currency (see HMRC cryptoassets manual CRYPTO22200). The same CGT matching rules apply — Same Day Rule, Bed & Breakfast Rule, and Section 104 Pool. Every disposal — sell, swap, or spend — is a taxable event. Converting between tokens (e.g. BTC to ETH) counts as a disposal of BTC and an acquisition of ETH.

Upload your Binance trade history CSV and CGT Calculator applies all HMRC matching rules automatically, including trades between crypto pairs and stablecoin conversions. Binance support is currently in beta.

Yes. The CGT report maps directly to HMRC Self Assessment form SA108 (Capital Gains). It provides total disposal proceeds, total allowable costs, and net gains or losses for the tax year — the exact figures you enter on SA108.

The report includes a full audit trail showing how each disposal was matched (Same Day, Bed & Breakfast, or Section 104), so you can verify every calculation. Download as PDF to keep with your tax records.

Offshore reporting funds — both accumulating (e.g. Vanguard VWRP, VUAG) and distributing (e.g. VWRL, VUSA) — are subject to Excess Reportable Income (ERI) rules per HMRC HS265. Accumulating funds typically have a large ERI figure because income is retained inside the fund; distributing funds usually have a small or zero ERI. Either way, any excess must be reported, and the ERI also increases your Section 104 Pool cost basis to prevent double taxation on disposal.

CGT Calculator has 3,500+ ERI entries built in for Vanguard and iShares funds. When you upload transactions containing these funds, ERI adjustments are applied automatically. See the ERI documentation for the full list of supported funds.