- Ensure that you are entering the correct Password.
- Check that your username is entered properly. If you have multiple Gmail accounts and your browser is set to auto-fill account fields, make sure it hasn’t auto-filled using a different account name.
- Determine if your Gmail account has been compromised and is being used by someone unauthorized.
- Determine if you’ve recently enabled Google’s two-step verification process. Two-step verification means that on top of your username and password, each time you log in you’ll need to enter a verification code that is sent to your phone as an automated voice message or text message.