Amazon S3 Cookbook

Walkthrough 2: To grant cross-account bucket permissions

If you own several AWS accounts (for example, Account A and Account B for different projects) and grant permissions to access the resources such as buckets or objects between the accounts, for example, you want to grant permissions that Account A allows Account B to access the objects or buckets of Account A, you can grant such permissions using cross-account permissions.

The following diagram shows how the AWS account A grants permissions to the S3 bucket, and the Admin IAM user in the AWS account B delegates permission to a different IAM user in its account and for this walkthrough.

To summarize, ...