Adding Sandbox Tester in iTunes Connect with an existing Apple account

Question

I\'m trying to add sandbox testers in iTunes Connect. But I\'m getting this error:

The email address you entered already belongs to an existing Apple acco

Answer 1

The email cannot be associated with an existing account, please see the link below.

Because the email address used to create a sandbox tester account can't be associated with any existing Apple account, consider creating a dedicated email address for each sandbox tester.

https://developer.apple.com/library/ios/documentation/LanguagesUtilities/Conceptual/iTunesConnect_Guide/Chapters/SettingUpUserAccounts.html