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

I fixed this by creating a brand new (free) Google account myappsandbox@gmail.com and adding that as a new sandbox tester. This makes a new Apple ID for that email address. It's a pain but it worked.