Forex trading in the UK is subject to HMRC tax rules, which allow traders to claim relief on losses incurred during trading. HMRC considers forex trading as a form of investment subject to capital gains tax (CGT) rules, with the first £3,000 of losses or gains being exempt from tax. For the 2025/26 tax year, traders can offset losses against future profits and carry forward excess losses to future years.

HMRC Forex Tax Rules

Under HMRC rules, forex trading is considered self-assessment, meaning traders must report gains and losses on their tax return annually. The submission deadline is 31 January following the end of the tax year—for the 2025/26 tax year, this is 31 January 2027. Traders must maintain accurate records of all trades, including dates, times, amounts, and resulting profits or losses.

Claiming Loss Relief

To claim loss relief, calculate your overall gain or loss for the tax year by totalling all profits and losses from each trade. If the result is a loss, you can offset it against future profits or carry it forward to future years. For example, a loss of £10,000 in the 2025/26 tax year can be offset against profits in the 2026/27 tax year. Losses can be carried forward for up to 4 years before expiring.

Record Keeping and Audit

Accurate record keeping is essential for claiming loss relief. HMRC may request to see trade records, including dates, times, amounts, and profits or losses. Keep records for at least 6 years in case of audit, and ensure they are complete and accurate. This includes spreadsheets, trading statements, and other supporting documents from your trading platform.

Audit and Investigation

During an audit or investigation, HMRC may request trade records and details about your investment strategy and trading methods. Provide complete and accurate information to avoid potential penalties or fines. This includes maintaining records of all trades from your trading platform, with dates, times, amounts, and resulting profits or losses.

Time Limits for Claiming Loss Relief

Traders must claim loss relief within 4 years of the tax year in which the loss occurred. A loss incurred in the 2025/26 tax year must be claimed by 31 January 2030. Failure to claim within this timeframe means the loss expires and cannot be offset against future profits.

Example of Loss Relief

Suppose you incur a loss of £20,000 in the 2025/26 tax year and have a gain of £10,000 in the 2026/27 tax year. You can offset the loss against the gain, reducing your taxable gain to £0, and carry forward the remaining £10,000 loss to future years. This approach reduces your overall tax liability and ensures you pay only what is due.