Try these steps in sequence to resolve the sign-in issues:
1. Verify that you are using the correct email and password combination. If you have more than one Amazon account with the same email address but different passwords, use the corresponding password for each account.
2. Ensure that there are no extra spaces in your password. This can happen when you copy and paste your password from somewhere else.
3. Verify that you entered the most recent Two-Step Verification
code you have received, if you are prompted to enter one.
4. Clear your browser cookies and cache or try logging in with a different browser or device.
5. Use the Password Assistance page
to verify whether the email address you are using is the one registered in our system.
6. If yes, change your password using the Password Assistance page.
7. Log in to Seller Central
using your new e-mail/password combination.
If these steps do not resolve the sign-in issue, it is likely that your email and password combination is not associated with an active Seller Central account. If you did not deactivate your account, click here