How to Set Up free tier and custom billing alerts in AWS

1. Search for Billing in the search bar and select it.
2. In the left hand navigation bar select Billing preferences
3. Under the Cost Management Preferences section, select the check boxes for Receive Free Tier Usage Alerts and Receive Billing Alerts.
4. Enter your email address into the text input box under Receive Free Tier Usage Alerts.
5. Select Save preferences.
6. In the services search bar, type in CloudWatch and select it.
7. If necessary, change the Region in the upper right corner to US East (N. Virginia). Billing metric data is stored in this Region and represents worldwide charges.
8. In the navigation pane, choose Alarms, then click Create Alarm.
9. Choose Select metric. In the search bar under Metrics, type in Billing, then choose Billing >Total Estimated Charge. If you don’t see Billing or the Total Estimated Charge metric, you may need to go back a few steps to enable billing alerts from the Billing preferences page.
10. Select the check box next to EstimatedCharges, and choose Select metric.
11. Under Conditions, choose Static.
12. For Whenever EstimatedCharges is, choose Greater.
13. For then, enter the monthly amount (this should be whatever number you are comfortable with. For example, 10) that must be exceeded to trigger the alarm. Choose Next.
14. In the Notification box, for Alarm State Trigger, select In alarm. Under Select an SNS Topic, choose create a new topic to be notified.

Amazon Simple Notification Service (Amazon SNS) is a service that publishes messages to a topic which delivers the message to all topic subscribers.

14. Enter a topic name. The name must be unique. Then, type in your email to receive the notification. NOTE: You will get an email in your inbox asking you to confirm your subscription to this topic. By confirming, you’re ensuring that you will get notifications when your estimated billing charges rises above your threshold.Click Create Topic. Then, select Next.
15. Enter in an alarm name and description. The name must contain only ASCII characters.
16. Under Preview and create, confirm that the information and conditions are what you want, then choose Create alarm.

References

[1] Coursera