You should keep a record of all your crypto transactions, both online within the exchange and in a backup CSV file. For tax purposes, you should keep a record of the type and amount of currency used for the transaction. Also, you note whether it was bought, sold, earned, or exchanged, as well as the date of the transaction. Keeping a record of the value at the moment of transaction, as well as any bank statements, might be handy. To simplify the whole process, you can always rely on some of the best crypto tax software from this list to automate keeping track of your crypto and taxes due on it.