How to Set Up AWS CloudWatch Alarm for Billing Alerts

To set up a CloudWatch alarm for billing, go to the AWS Billing console, enable billing alerts, then create a CloudWatch alarm on the EstimatedCharges metric. Set your threshold amount and notification options to get alerts when your AWS costs exceed that limit.

Syntax

The main components to set up a billing alarm in CloudWatch are:

• MetricName: Use EstimatedCharges to track your AWS costs.
• Namespace: Use AWS/Billing which contains billing metrics.
• Threshold: The cost amount that triggers the alarm.
• ComparisonOperator: Usually GreaterThanOrEqualToThreshold to alert when costs exceed the threshold.
• EvaluationPeriods: Number of periods to evaluate before triggering.
• AlarmActions: The notification action, like sending an email via SNS.

bash

aws cloudwatch put-metric-alarm \
  --alarm-name "BillingAlarm" \
  --metric-name EstimatedCharges \
  --namespace AWS/Billing \
  --statistic Maximum \
  --period 21600 \
  --evaluation-periods 1 \
  --threshold 100 \
  --comparison-operator GreaterThanOrEqualToThreshold \
  --alarm-actions arn:aws:sns:us-east-1:account-id:topic-name \
  --dimensions Name=Currency,Value=USD

Example

This example creates a CloudWatch alarm named BillingAlarm that triggers when your estimated AWS charges in USD reach or exceed $100. It sends a notification to an SNS topic to alert you.

bash

aws cloudwatch put-metric-alarm \
  --alarm-name "BillingAlarm" \
  --metric-name EstimatedCharges \
  --namespace AWS/Billing \
  --statistic Maximum \
  --period 21600 \
  --evaluation-periods 1 \
  --threshold 100 \
  --comparison-operator GreaterThanOrEqualToThreshold \
  --alarm-actions arn:aws:sns:us-east-1:123456789012:BillingAlerts \
  --dimensions Name=Currency,Value=USD

Output

An alarm named 'BillingAlarm' is created and will notify the SNS topic 'BillingAlerts' when estimated charges reach $100 or more.

Common Pitfalls

• Billing Alerts Not Enabled: You must enable billing alerts in your AWS account before CloudWatch billing metrics are available.
• Wrong Region: Billing metrics are only available in the us-east-1 region, so run commands or create alarms there.
• Incorrect Dimensions: Always specify Name=Currency,Value=USD to monitor charges in US dollars.
• Missing SNS Subscription: Ensure your SNS topic has confirmed email subscriptions to receive notifications.

bash

aws cloudwatch put-metric-alarm \
  --alarm-name "BillingAlarm" \
  --metric-name EstimatedCharges \
  --namespace AWS/Billing \
  --statistic Maximum \
  --period 21600 \
  --evaluation-periods 1 \
  --threshold 100 \
  --comparison-operator GreaterThanOrEqualToThreshold \
  --alarm-actions arn:aws:sns:us-east-1:123456789012:BillingAlerts \
  --dimensions Name=Currency,Value=USD

# Wrong region 'us-west-2' used above. Correct region is 'us-east-1'.

Quick Reference

• Enable billing alerts in AWS Billing preferences.
• Use us-east-1 region for billing metrics.
• Set MetricName to EstimatedCharges and Namespace to AWS/Billing.
• Specify Currency=USD dimension.
• Use SNS to receive email notifications.

Key Takeaways

Enable billing alerts in AWS Billing console before creating alarms.

Billing metrics are only available in the us-east-1 region.

Use the EstimatedCharges metric with Currency=USD dimension for cost monitoring.

Set a threshold and connect an SNS topic to get notified.

Confirm SNS subscriptions to receive alarm notifications.