Coinbase sign in gives you the power to buy and sell cryptocurrencies after adding a payment method. You can add a debit or credit card and bank account to buy the cryptocurrencies. You can add a bank account to Coinbase by visiting the account section of your profile. Once after adding the bank account, you are all set to start buying and selling the cryptocurrencies. The process to add a bank account is not much difficult and we have mentioned the clear steps to do so below on this page. Make sure to provide the correct username and password details to log in to your Paypal login account.