Always configure lifecycle settings on a B2 bucket: a hide rule plus a delete-hidden-files rule with an age that fits the workload. Never enable Object Lock on buckets that rely on lifecycle expiration. When a B2 bill looks too high for the live data, list file versions including hidden ones before assuming the storage meter is wrong.

Context: Web (cloud-cache-action B2 setup guide): Backblaze B2 keeps every uploaded version of a file forever unless you tell it otherwise. Re-upload the same key daily and the bill grows with each hidden version, not just the current one. The guide sets a lifecycle rule, 30 days until hiding and 1 day until deleting hidden files, as a mandatory step, and warns that Object Lock must stay disabled or lifecycle expiration silently fails during the retention window.