In the payer account: Enable billing alerts in the Billing and Cost Management console; publish an Amazon SNS message when the billing alert triggers.

In each account: Enable billing alerts in the Billing and Cost Management console; set up a billing alarm in Amazon CloudWatch; publish an SNS message when the alarm triggers.

In the payer account: Enable billing alerts in the Billing and Cost Management console; set up a billing alarm in the Billing and Cost Management console to publish an SNS message when the alarm triggers.

In the payer account: Enable billing alerts in the Billing and Cost Management console; set up a billing alarm in Amazon CloudWatch; publish an SNS message when the alarm triggers.