To check your account balance online with Banamex, you can visit their official website and log into your online banking account. Once you are logged in, you will typically find an overview of your accounts, which includes your current balance for each account you hold. If you have not yet registered for online banking, you will need to complete that process first. During registration, you may be asked to provide personal information and account details to verify your identity. It is also advisable to ensure that the website is secure to protect your information. For specific instructions or assistance related to your account, it would be beneficial to refer to their help section on the website or look for contact information for further inquiries.