The United Kingdom’s tax authority issued a paper that sets forth their views on crytocurrencies.
It defines crypto-assets but surprisingly says that “HMRC does not consider cryptoassets to be currency or money.”
And the tax treatment of cryptoassets will depend upon the nature and use of the digital item and not its definition. Thus, the taxation differs among exchange, utility and security tokens.
“Individuals will be liable to pay Income Tax and National Insurance contributions on cryptoassets which they receive from: their employer as a form of non-cash payment, mining, transaction confirmation or airdrops.”
You will pay capital gains tax on trading transactions.
And tough luck if you lose your private key or your cryptoassets are stolen. The government still believes that you own that asset.