Tastytrade UK Tax Guide — Capital Gains Tax on Stocks and Options

Tastytrade (formerly tastyworks) has built a following among UK options traders who want access to US markets with a proper options chain. But when tax season rolls around, UK users are essentially on their own — tastytrade is a US broker and has zero interest in HMRC compliance. Here’s how to sort it out.

Tastytrade’s UK tax problem

Tastytrade doesn’t know or care about UK tax rules. Their platform is designed for US taxpayers, so any tax reports they generate use US rules (FIFO cost basis, short-term vs long-term holding periods). None of that applies to you as a UK investor.

What you need to do: export your raw transaction history and apply HMRC’s rules yourself. The US-style reports are useless for SA108.

Exporting your transaction history

In the tastytrade desktop app or website: go to History → Transactions → set the date range to cover your full trading history → export as CSV.

The CSV format is dense but comprehensive. Key columns include:

Tastytrade gives you granular detail — much more than Robinhood’s CSV. The option fields (call/put, expiry, strike) are broken out into separate columns rather than crammed into a description string. This actually makes programmatic parsing easier.

Transaction types you’ll encounter

Tastytrade’s CSV includes various row types. For CGT purposes, you care about:

Equity trades: BUY_TO_OPEN and SELL_TO_CLOSE for stocks. Standard buy/sell — goes through HMRC share matching rules.

Option trades: BUY_TO_OPEN, SELL_TO_OPEN, BUY_TO_CLOSE, SELL_TO_CLOSE for options. Plus assignment, exercise, and expiration events.

Receive Deliver: These represent the stock delivery side of an option assignment or exercise. If your put was assigned, you’ll see a “Receive Deliver” row for the shares you acquired. This is the stock trade that needs to be linked to the option premium under TCGA s.144.

Rows marked as interest, fees, or transfers are not CGT events — ignore them.

The USD conversion challenge

Everything on tastytrade is in US dollars. You need HMRC’s monthly exchange rates to convert each transaction to GBP. The rate for, say, January 2025 is applied to all trades in January 2025.

This is particularly important for options traders who might open a position in one month and close it three months later. The open and close are converted at different rates, which means your GBP gain can differ meaningfully from your USD gain.

Options on tastytrade — the full picture

If you’re trading options on tastytrade, the CGT treatment follows the same principles as Robinhood UK options (TCGA s.144), but the CSV format is different. Key scenarios:

Selling premium (the wheel strategy): Many tastytrade users run the “wheel” — sell cash-secured puts, get assigned, sell covered calls. Each leg has its own CGT treatment. Put expires = premium is a gain. Put assigned = premium reduces stock cost. Call expires = premium is a gain. Call assigned = premium added to stock proceeds.

Spreads: If you trade vertical spreads, iron condors, or other multi-leg strategies, each leg is a separate chargeable asset. HMRC doesn’t have a concept of “spread” — each option is its own disposal. This means a losing spread leg creates a loss that offsets the winning leg, but they’re reported separately.

Rolling: When you close one option and immediately open another (a “roll”), that’s two distinct events. The close is a disposal (gain or loss). The open starts a new position. The 30-day bed and breakfast rule doesn’t apply to options in the same way as shares, because each option with a different strike or expiry is a different asset.

Fees on tastytrade

Tastytrade’s fee structure for non-US clients:

These fees appear in the CSV and should be included in your CGT calculation. They’re not huge individually, but across hundreds of option trades they add up.

Putting it together

The workflow for tastytrade UK CGT:

1. Export your full transaction history CSV from tastytrade.

2. Upload to TaxBull — it auto-detects the tastytrade format and handles both equity and option columns.

3. Enter HMRC exchange rates (TaxBull can auto-fetch these).

4. Calculate — stocks go through HMRC matching rules, options through FIFO with s.144 assignment linkage.

5. Review the results: stocks in SA108 Boxes 23-30, options in Boxes 14-22.

TaxBull is one of the only UK CGT calculators with native tastytrade support. Most others require manual reformatting — which is error-prone when you’re dealing with hundreds of option trades.

This guide is for informational purposes only. Tastytrade is regulated in the US by FINRA/SEC, not by the FCA. UK tax obligations are your responsibility. Consult a qualified tax professional.