AWS CloudTrail enables event logging across AWS services, but when multiple trails are configured to log overlapping events — especially data events — it can result in redundant charges and unnecessary storage or ingestion costs. This commonly occurs in decentralized environments where teams create trails independently, unaware of existing coverage or shared logging destinations.Each trail that records data events contributes to billing on a per-event basis, even if the same activity is logged by multiple trails. Additional costs may also arise from delivering duplicate logs to separate S3 buckets or CloudWatch Log groups. While separate trails may be justified for audit, compliance, or operational segmentation, unintentional duplication increases both cost and operational complexity without added value.