AWS bill line item
TimedStorage-SIA-ByteHrs
GB-month storage charge for objects held in the S3 Standard-IA class. It's cheaper per-GB than Standard, but with per-GB retrieval fees and a 30-day minimum storage duration per object.
S3 Standard-Infrequent Access storage
Verified against official AWS documentation last checked
Why it shows up
Lifecycle rules that auto-transition objects to IA to save money can backfire if the workload re-reads that data often. Retrieval fees plus the minimum-duration penalty can make it more expensive than leaving it in Standard.
Small objects are a hidden trap: anything under roughly 128 KB is billed as if it were that minimum size, so transitioning many small files to IA can increase, not reduce, total storage cost.
How to cut it
- Only transition objects with infrequent access, confirmed via storage-class analytics first.
- Avoid transitioning small objects to IA. The minimum billable size erases the savings.
- Make sure objects will live past the 30-day minimum before transitioning, or accept the early-delete charge as a known cost.
- Consider an automatic tiering class instead of manual IA lifecycle rules when access patterns are unpredictable.
How to read a usage type
TimedStorage-SIA-ByteHrs carries no region or direction token, so there's nothing to break down here.
Source
Source: AWS docs →Found TimedStorage-SIA-ByteHrs on your own bill?
Drop your Cost Explorer CSV into the AWS Bill Analyzer. It'll flag line items like this one on your own bill and link straight back to the fix.
Analyze your own bill →The meter you don't watch still grows.
Waste rarely hides in the service you check every week. CostMon watches every meter on your stack, including the ones you forgot were running.