Generally, signing up at Revolut should not cost anything if you follow our instructions. You only need to top-up your account with €10 (which you can later on spend or simply transfer back to your own bank account). There are no ongoing expenses, e.g. an annual fee or account management fee. The exchange rate, however, is decided by Revolut and could thus have a hidden fee. Additionally, Revolut offers further services for their Revolut Premium or Metal accounts, which then have a monthly fee.