Before getting started, make sure you have an IAM user that has access to the Billing Dashboard. If you are working with consolidated accounts due to being in an AWS organization, create this alarm in the payer account.

To get started, make sure that monitoring of estimated charges is enabled for your personal or payer account.

To enable this: 

1. Open the Billing Console in your AWS account 
2. In the left hand pane, choose Billing Preferences
3. Then select Receive Billing Alerts
4. And then click Save Preferences 

Now we are ready to set up the Cloud Watch billing alarm:

1. Log into your AWS account that you want to set up the Billing alarm for
2. In the top search bar, search for “CloudWatch”
3. In the left hand pane under the “Alarms” section, click “All Alarms”
4. At the top right of the page, click the orange button “Create alarm”
5. Click “Select metric” 
6. In the metrics section, choose “Billing” and then choose “Total Estimated Cost”
7. Ensure to select the box for “EstimatedCharges” and then click “Select Metric” 
8. For the threshold type, choose “static” and then for Whenever EstimatedCharge is … choose “Greater”
9. For the next input, put the threshold value that will trigger your alarm 
   1. For this example we will choose $5K 
10. Then to continue, click “Next” 
11. Under the notification section select “Create new topic” 
    1. An SNS topic will be needed in this configuration because this service will be in charge of notifying you if the alarm becomes active via your email 
    2. Specific a Unique Topic Name and add the emails of the people you want to be notified for this alarm
12. You can then name your alarm, input a description and then “Create alarm” 
13. Done!

It’s as easy as that! You now have an automated AWS CloudWatch Alarm that will notify you by email whenever the threshold value you specified is surpassed. 

Interested in setting up more AWS related services? Check out this article on how to set up SSO CLI Access!