• True
• False

The correct answer is: False

Explanation: The statement “AMC users have access to all AMC instances in an account by default” is False.

Access to individual AMC instances (such as advertiser instances, sandbox environments, or partner-managed instances) is controlled and must be explicitly granted, users do not automatically have access to all instances.

Reference content: From the official Amazon documentation (AMC overview):

“Multiple users and partner organizations can now access one AMC instance at the same time. This enables more scalable AMC usage and operations, and it’s especially beneficial for partners handling multiple AMC instances across advertisers.”

This means access is instance-specific and must be set individually—users are not granted all-instance access by default.