IAM Policies With Principal Org Ids

Let’s say you want to write an AWS IAM policy to allow anybody under your AWS organization to perform an action, like access s3 buckets.

You can do this by using the PrincipalOrgId condition.

{
  "Sid": "Allow org access to all s3 buckets",
  "Effect": "Allow",
  "Principal": {
    "AWS": "*"
  },
  "Action": ["s3:*"],
  "Resource": "*",
  "Condition": {
    "StringEquals": {
      "aws:PrincipalOrgID": "o-xxxxxxxxxxx"
    }
  }
}

Setting a condition like the above role will restrict access to only people within your organization. This is useful if you have multiple AWS accounts with shared resources, like a centralized ECR.