🇬🇧 UK Capital Gains Tax.
Calculated Correctly.

DATEASSETACTIONAMOUNTSTATUS
15/03/24AAPLSELL£4,280
15/03/24AAPLBUY£3,120
18/01/24VWRLSELL£2,450
02/02/24VWRLBUY£2,100
05/09/23TSLASELL£1,890
TOTAL GAIN£0.00
Ready for Self Assessment
Free to start →

Stocks. Options. Crypto. Multi-broker. HMRC built in.

Options

Each option is a separate CGT asset per HMRC rules.
Exercise, assignment, expiry — every outcome calculated correctly.

Iron Condor
SELL95 Put-$2.00 × 100
BUY90 Put+$0.50 × 100
SELL110 Call-$1.80 × 100
BUY115 Call+$0.40 × 100
4 separate CGT disposals
  • Covered Call
  • Cash-Secured Put
  • Protective Put
  • Bull Call Spread
  • Bear Put Spread
  • Bull Put Spread
  • Bear Call Spread
  • Iron Condor
  • Iron Butterfly
  • Long Straddle
  • Long Strangle
  • Short Straddle
  • Short Strangle
  • Calendar Spread
  • Diagonal Spread
  • Collar
  • LEAP Options
  • Ratio Spread
  • Jade Lizard
  • Poor Man's CC

60+ strategies supported

Multi-Broker

Consolidate stocks, options, and crypto from all your brokers
into a single HMRC rules-based report.

SA108-readyPDF

Pricing

We prepared something proper British for you.
Browse the museum for free, or pick a heartier portion.

Museum

33 transactions

  • Stock transactions
  • Interest & income
  • Awards
  • Multi‑broker

Tea with Milk

100 transactions

  • Stock transactions
  • Interest & income
  • Awards
  • Options trading
  • ERI data
  • Multi‑broker
Coming soon

Fish and Chips

500 transactions

  • Full privacy
  • Stock transactions
  • Interest & income
  • Awards
  • Options trading
  • ERI data
  • Multi‑broker

Coming soon

High Tea

Unlimited transactions

  • Full privacy
  • Stock transactions
  • Interest & income
  • Awards
  • Options trading
  • ERI data
  • Multi‑broker
  • Options analytics

Frequently Asked Questions

HMRC share matching, options taxation, crypto, broker support,
and everything else you need to know.

Is CGT Calculator free to use?

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Yes. The Museum tier (up to 33 stock transactions) and Tea with Milk tier (up to 100 transactions including options) are both completely free. Just sign in with Google or a magic link — no credit card needed. Upload your broker CSV, get your HMRC-compliant report, and download the PDF.

Is my data safe and private?

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Your data is used only to generate your tax report. We do not use advertising cookies or tracking scripts.

With Fish & Chips and High Tea tiers, all calculations run entirely in your browser — nothing is sent to the server.

What are HMRC share matching rules?

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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.

How are stock options taxed for UK CGT?

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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.

How is an iron condor taxed under HMRC rules?

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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.

What happens when an option is assigned or exercised?

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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.

Which brokers and exchanges are supported?

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Eight brokers and exchanges: Interactive Brokers (IBKR), Charles Schwab, Trading 212, Freetrade, Morgan Stanley, Revolut, Binance, and Coinbase (last two 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.

How is cryptocurrency taxed for UK CGT?

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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.

Can I use this for Self Assessment?

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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.

How does it handle offshore ETFs like Vanguard VWRL?

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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.