AWS Backup for s3 - Copy to another account

Question

I'm attempting to use AWS backup to send an s3 backup from one account to another. I've setup all the requirements and backups in my source account are working fine. The issue comes when copying to another account. Looking at this guide there is no mention of this functionality being a limitation. My backup rule includes the copy step, however when the plan is triggered the copy never happens or provides any indication if there was an error.

If I try to manually kick off a backup and copy to another account the option is greyed out.

I've attempted to copy a snapshot and continuous backup, neither work. I'm guessing this is due to how s3 backups work? I've tested with Dynamo and the copy feature works fine.

Answer 1

Found an answer here, looks like it's not supported.

Answer 2

Copying from one source AWS account to another target AWS account is actually supported, but the target AWS account must be part of the same AWS Organization.

If you were to press the "Info" link in the screenshot in the question, you would see the following pop up:

External vault ARNs allow you to specify a backup vault in another account as the copy destination. This account must belong to the same organization as the account creating the backup. You can configure which accounts are in your organization in the AWS Organizations Console.

Ensure you configured the external vault with an access policy that allows another account to copy into it.