Charges exceed budget notifications by multiples

Hi,

Yes, unfortunately this situation can occur, as described in the AWS documentation.

There can be a delay between when you incur a charge and when you receive a notification from AWS Budgets for the charge. This is due to a delay between when an AWS resource is used and when that resource usage is billed. You might incur additional costs or usage that exceed your budget notification threshold before AWS Budgets can notify you.

As Mikel said, unfortunately this situation can occur, as described in the AWS documentation.

For example, you can automatically enroll your account under Cost Anomaly Detection with Value as your budget threshold, and let it work. It should be "quicker" and match your use case.