Very few jurisdictions have written a separate tax regime for cryptocurrency. Most assess it under the categories that already exist — income, capital gains, business profits, consumption tax — which means the outcome turns on how an activity is characterised rather than on any crypto-specific rule. That characterisation is the first question in every case, and it is one a local adviser answers, not a forum.
The distinction that decides most outcomes is between receiving and disposing. Crypto received as payment for work, as mining or staking rewards, or as an incentive is generally income, valued in local currency at the moment of receipt, and the fact that no bank account was involved changes nothing. Crypto disposed of is generally assessed on the difference between what it cost and what it realised. The awkward cases sit between the two: a reward that is income when received and then also produces a gain when sold is taxed twice on two different bases, which is correct and surprises people.
A trade between two crypto assets is a disposal almost everywhere. This is the single most common misunderstanding in the subject: swapping one token for another is treated as selling the first, and a year of active trading can produce a substantial liability without a single withdrawal to a bank. The same applies to spending crypto on goods, to bridging in some readings, and to paying a fee in kind.
Whether an activity is investment or trade changes the regime again. Someone dealing frequently, systematically and with the character of a business is usually assessed on business profits rather than on capital gains, with different rates, different loss treatment and different deductions. The tests are the ordinary ones a jurisdiction already applies to any other asset, and they turn on frequency, organisation and intention rather than on volume alone.
Several questions are genuinely unsettled in most places rather than merely unclear to the taxpayer, and it is more useful to name them than to paper over them: the timing of recognition for staking and other protocol rewards, the treatment of an airdrop received before any market for it exists, which cost-basis method may be used across many small acquisitions, and whether a loss on an asset that has become worthless is deductible and when. Where these matter to a real position, they are advice questions.
What is not unsettled anywhere is record-keeping. Substantiating a return is the taxpayer's obligation, and crypto makes it harder rather than easier: transactions are spread across venues, wallets and chains, exchanges close and take their histories with them, and a price at a moment three years ago is not reconstructible from memory. Keeping dated records of every acquisition and disposal in local currency, at the time, including crypto-to-crypto trades, is the step that keeps a manageable question from becoming an unmanageable one later.