Yesterday I locked down the root account and noted "keep billing alerts up to date". Today is the other half of the front door: making sure a forgotten resource never turns into a surprise bill. AWS Budgets does that.
What AWS Budgets does
- You set a spending limit (or a usage limit) and AWS compares your actual and forecasted spend against it.
- When a threshold is crossed, it emails you (and can notify an SNS topic).
- Spend data is not instant. Billing data can lag, so treat alerts as an early warning, not a live meter.
Types of budget
| Type | Tracks | Good for |
|---|---|---|
| Cost budget | Dollars spent | Almost every learner |
| Usage budget | Units used, such as hours or GB | Watching a specific service |
| Savings Plans / Reservation budgets | Coverage and utilization | Later, when you commit to spend |
Two templates to start with
- Zero spend budget: alerts you as soon as your spend goes above the free tier. Ideal for a learning account.
- Monthly cost budget: you choose a monthly amount, and the console sets alerts at 85% of actual spend, 100% of actual spend and 100% of forecasted spend.
Hands-on: try it in your own account
- Sign in and open Billing and Cost Management, then Budgets.
- Choose Create budget and pick a template, such as Zero spend budget or Monthly cost budget.
- Name it, set the amount (for example 10 USD) and add the email addresses to alert.
- Review the thresholds and create the budget.
- Optionally, as the root user, turn on IAM user and role access to Billing information so your admin identity can see costs without using root.
Common mistakes
- Creating a budget but typing the email address wrongly.
- Setting only an actual-spend alert, so you hear about a problem after the money is gone.
- Forgetting that some services keep charging until you delete the resource.
- Using root every time to check the bill instead of enabling billing access for IAM.
Worth knowing next
Cost Explorer shows where your spend comes from, and Cost Anomaly Detection can flag unusual spikes. Budgets tells you that spend is rising. Those two help explain why.
Key takeaways
- Create a budget before you create any real resources.
- Alert on forecasted spend as well as actual spend.
- Give billing access to an IAM admin, not just root.
- Delete what you stop using.
Tomorrow I'll go one step further into securing access to the account.
Originally published on my blog. Part of #120DaysOfAWS.
