In many countries, cryptocurrencies are subject to tax. Trading, spending or selling your crypto are often taxable events. To calculate your taxes, you will need to consider your capital gains and losses. You may also have to pay income taxes if you receive crypto as payment.
Every jurisdiction is different, so make sure you consult a tax advisor. Tax authorities frequently cooperate with crypto exchanges to track crypto transactions. If you attempt to evade tax, you can end up with financial penalties and even harsher punishments.