If the same email address has been used as the root email address for a new AWS and for interacting with Amazon.com, those two accounts are inextricably linked forever.
Example
If you have an Amazon.com shopping account with email address xyz123@cornell.edu, and create an AWS account with that same email address (xyz123@cornell.edu), the Amazon.com account and the AWS account become linked (forever).
Ramifications
In this situation:
- If you were to change the root email address for the AWS account, it would also change the email address for the Amazon.com account.
- If you were to change the email address for the Amazon.com account, it would also change the root email address for the AWS account.
- AWS/Amazon cannot manually unlink or decouple these accounts.
- If the Amazon.com account is closed, the AWS account will get closed.