Unattached Elastic IP Addresses
CostLens detects Elastic IPs that are allocated but not associated with any instance, and releases them to eliminate the idle charge.
AWS charges $0.005 per hour (~$3.60/month) for every Elastic IP (EIP) that is allocated but not associated with a running instance. CostLens detects unattached EIPs and recommends releasing them to eliminate this unnecessary charge.
Releasing an EIP is permanent
Once an Elastic IP is released, the IP address is returned to AWS's pool and you cannot reclaim it. If any DNS records, firewall rules, or application configs reference this IP, they will break. Verify the IP is not in use before applying this fix.
How it works
CostLens lists all Elastic IPs
Calls ec2:DescribeAddresses to retrieve all EIPs allocated to the account in each region.
Checks for association
Flags any EIP that has no AssociationId — meaning it is not attached to a running instance or network interface.
Calculates monthly cost
Each unattached EIP costs a fixed $3.60/month. Multiple unattached EIPs are flagged as separate findings.
Releases the EIP on fix
When you apply the fix, CostLens calls ec2:ReleaseAddress to return the IP to AWS's pool.
Before applying the fix
Check whether the IP address is referenced anywhere:
- DNS records (A records pointing to this IP)
- Security group inbound rules allowing traffic from this IP
- Application configuration files or environment variables
- Firewall or VPN allow-lists
If the IP is referenced in any of these, update those references before releasing it.
What to do
Option 1 — Release the EIP (recommended if unused)
Apply the fix in CostLens. The EIP is immediately released and the hourly charge stops.
Option 2 — Dismiss if planned for future use
If the EIP is being held for an upcoming deployment or migration, dismiss the recommendation with a note. CostLens will stop flagging it.
Severity levels
Each unattached EIP costs approximately $3.60/month, which falls into the low severity band. Accounts with many unattached EIPs will have multiple separate findings.
| Severity | Monthly cost |
|---|---|
| low | <$20 (typically 1–5 unattached EIPs) |
Required IAM permissions
Included in the CostLens IAM policies from AWS Accounts:
ec2:DescribeAddresses
ec2:ReleaseAddress