Backup and tag copy
You can copy backups to multiple Amazon Web Services accounts or Amazon Web Services Regions on demand or automatically as part of a scheduled backup plan for most resource types, though backups in cold storage or archive tiers cannot be copied. See Feature availability by resource for details.
You can also automate a sequence of cross-account and cross-Region copies for most supported resources, except for Amazon RDS and Aurora. For Amazon RDS and Aurora snapshots, Amazon Backup only supports automating either cross-account or cross-Region copies due to how those services create their encryption keys (copying a Multi-AZ DB cluster snapshot is not supported).
Some resource types have both continuous backup capability and cross-Region and cross-account copy available. When a cross-Region or cross-account copy of a continuous backup is made, the copied recovery point (backup) becomes a snapshot (periodic) backup (not available for all resource types that support both backup types). Depending on the resource type, the snapshots may be an incremental copy or a full copy. PITR (Point-in-Time Restore) is not available for these copies.
Copies retain their source configuration, including creation dates and retention period. The creation date refers to when the source was created, not when the copy was created.
NOTE: The source configuration overrides its copy’s expiration setting, even if the copy is set to never expire; a copy set to never expire will still retain its source’s expiration date.
If you want your backup copies to never expire, either set your source backups to never expire or specify your copy to expire 100 years after its creation.