Please note that this is a general summary of taxation of CFDs in the UK at the time of writing, tax laws are complex and can change, so please take professional advice. In general, contracts for difference are taxed, in the UK, in the same way as any derivative, and in much the same way as any security. Capital gains tax How do HMRC tax gains (and losses ) made on CFD's (Contracts for Differences) which I am sure you know allows clients to take out a contract on the rise or fall of stock,index,forex,ETF or commodity without physically owning the underlying instrument itself. HI there. I need advice on uk tax for trading forex. CFDs are subject to the usual tax on capital gains, but are exempt from stamp duty – even when the underlying asset is a UK security. Stamp duty is normally payable at around 0.5% on the total transaction value of share sales, but is not applicable for CFD transactions …