In the organization's management account, configure AWS Budgets to create a daily budget with an 80% alert threshold. Use Amazon Simple Notification Service (Amazon SNS) to send notifications to the finance team.

In the organization’s management account, set up the organizational view feature in AWS Trusted Advisor for cost optimization. Create a report with an 80% alert threshold and configure email notifications for the finance team.

Register the organization with AWS Control Tower and activate the optional cost control guardrail, setting it to 80%. Configure notifications via Amazon Simple Notification Service (Amazon SNS) for the finance team.

Configure member accounts to store daily AWS Cost and Usage Reports in an Amazon S3 bucket within the organization's management account. Schedule daily cost calculations using Amazon Athena and set up Amazon CloudWatch alerts for 80% budget usage, with notifications sent via Amazon Simple Notification Service (Amazon SNS) to the finance team.