There is no unique policy in taxing cryptocurrency. The rules for paying a tax on cryptocurrencies may be different for each country. This depends on how the laws of each country define cryptocurrency, and what type of tax system is utilized in the particular country. Some countries have flexible regulations on cryptocurrency, while some treat it as a source of income you have to report. Right now, most countries recognize cryptocurrencies as digital assets or property, which attracts capital gains. This is why you will probably have to pay some sort of income tax or tax on capital gains in the country where you reside.