If you've forgotten your Citibank username or password, visit the Citibank login page and click on the "Forgot Username/Password?" link. Follow the prompts to verify your identity using your registered mobile number or email. For username recovery, you'll receive an email with your username. To reset your password, you may need to answer security questions or receive a verification code. If you encounter issues, contact Citibank customer service for further assistance. Always create a strong password and update it regularly to ensure the security of your online banking account.