What the issue is
EBS volumes persist independently from EC2 instances. If an instance is terminated without deleting the disk, that volume continues billing until someone explicitly snapshots or removes it.
This is common after autoscaling changes, temporary environments, one-off incident response instances, and manual console cleanup.
- Detached volumes left behind after EC2 termination
- Old root disks from migration or disaster-recovery exercises
- Forgotten data volumes in secondary regions