How to monitor multiple AWS accounts in single AWS account for cost perspective

I'd split your question in two parts:

Cost:

AWS Organization is a service, which you can consider to have consolidated billing, where you would have an organization or organizations of organizations(often called org unit -OU). This way, you can manage/monitor cost from Management Account itself.

Within an Organization Unit(OU), you can have multiple AWS Accounts and OUs. Root Organization is parent of all, which contains management account. Through management account, you can monitor cost incurred by each account.

All you need to do is, when you'd have AWS Organization created and all your aws accounts linked to this org/management account:

1. Go to Cost explorer in management account
2. In the group by field, choose Linked Account
3. You'll see cost incurred by each account, you can further drill it down for a specific service by selecting a specific service in service filter.

AWS Org References:

• AWS Organization FAQs, which would answer many of the commonly asked questions. Please take a look at second question here in this FAQ, which particularly talks for your ask.

• AWS Organization Documentation

• Benefits of AWS OUs

Alerts:

AWS config and cloudtrail are those two services, which can be used in an AWS organization and monitor all accounts within the org:

• Config Aggregator for an Org Blog Post

• AWS Config and AWS Organizations

• Managing AWS Config Rules Across All Accounts in Your Organization

• Organizational Cloudtrail

Hope you find this useful.

Comment here if you have additional questions, happy to help.

Abhishek

Hello, you can monitor multiple AWS accounts through a single AWS account using AWS Budgets if your accounts are part of an Organization. In the management account you can view the monitor costs for all accounts in your organization. This will allow you to manage your costs.

This article describes best practices for tracking and taking action on your AWS costs and usage with AWS Budgets: https://docs.aws.amazon.com/cost-management/latest/userguide/budgets-managing-costs.html

This documentation tells you how you can set up budget alerts from AWS Budgets in Amazon Chime and Slack by using AWS Chatbot: https://docs.aws.amazon.com/cost-management/latest/userguide/sns-alert-chime.html

AWS Organizations have a feature called Consolidated Billing, which can help track and combine all the AWS accounts bills into one to view the different information in each account: https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/consolidated-billing.html

These links will provide you with context regarding CloudWatch alarms: https://aws.amazon.com/about-aws/whats-new/2021/08/announcing-amazon-cloudwatch-cross-account-alarms/ https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/Cross-Account-Cross-Region.html

CloudWatch has some alarms you can set up for billing purposes. So, with the cross-account alarms you could set it up to have the cross-account alarms notify your one central account for any billing situations, say if that account goes over a specified amount.