Summary: Every Amazon Appstore developer’s account (https://developer.amazon.com/welcome.html) is linked to an Amazon.com account with same account e-mail id and password. Often developers will make changes to their Amazon.com account credentials without realizing that this will also impact their developer’s account.
For example, if you log into your Amazon.com account with the same account e-mail that is tied to your developer’s account, and change the password on this account, this will also change the password of your associated developer’s account. If you're having trouble signing into your developer’s account, here are some things to check:
Incorrect E-mail Address: Your e-mail address must be in this format: username@domain.com (or .net, .org, .edu, etc.). If you have more than one e-mail address, be sure that you're using the correct e-mail address and password combination for the account you are trying to access. Also, if your computer is set to auto-complete the e-mail, make sure it's the correct e-mail address listed.
Incorrect Password: If you're sure you're using the correct e-mail address, try to reset your password. For more information, go to: http://www.amazon.com/gp/help/customer/display.html?nodeId=201121280 If you are unsuccessful in using the "Forgot Your Password" tool, then please contact Amazon's Customer Service team for Account & Login issues at: https://www.amazon.com/gp/help/customer/account-issues/ref=ap_cs_forgot_pwd?ie=UTF8 The Amazon’s Customer Service team for Account & Login issues can be reached via E-mail, Phone and Chat.