From AnyCompany’s AWS account, invite Example Corp’s existing AWS management account to start the join process. Ensure that Organizations creates the OrganizationAccountAccessRole IAM role with the required permissions.

From Example Corp’s management AWS account, send an AWS Support request to AWS to add AnyCompany’s AWS account to the existing organization. Ensure that Organizations creates the OrganizationAccountAccessRole IAM role with the required permissions.

From Example Corp’s management AWS account, send an invitation to AnyCompany’s AWS account. Accept the invitation in AnyCompany’s account. Create an OrganizationAccountAccessRole IAM role with the appropriate managed IAM policy.

From AnyCompany’s AWS account, create an OrganizationAccountAccessRole IAM role with the appropriate managed IAM policy. Configure AnyCompany’s AWS account to be a member of Example Corp’s organization.