This is a variation of the previous Mistake #5: Forgetting to Clean Up Stale Resources, but curious enough to get its own post.  Users tend to forget that AWS charges for Elastic IPs only when they’re not in us (it’s a bit counter-intuitive even though the motivation is clear: preventing users to keep IP addresses reserved without ever using them).

At one cent per hour, cost might not seem to be a big issue here, yet we’ve found users with hundreds of Elastic IPs lying around not associated to any instance and running at thousands of dollars per year.

Check out the related Cloud Insight - Elastic IPs not in use

Keywords: allocated elastic ip, AWS charges, elastic IPs