Transfer some instance ownership

Short answer: No.

While you can transfer a whole account to a different organization you can't transfer EC2 instances between accounts. In this case, you can't transfer part of an account - only the whole account so you will need to look at some type of migration process. You might consider the Application Migration Service.

To expand on Brettski-AWS answer.

As Brettski-AWS mentioned you can only migrate whole accounts between AWS Organisations or update/transfer ownership to another individual or organisation, which moves all resources in the accounts.

By transfer ownership I assume you mean move them to a separate AWS account. There are a few ways to achieve this:

• AWS Application Migration Service: https://aws.amazon.com/application-migration-service/
• Share the AMI: https://repost.aws/knowledge-center/account-transfer-ec2-instance
• Share EBS Snapshot: https://repost.aws/knowledge-center/share-ebs-volume

In all cases this will allow you to move the data and re-provision the compute instance, but will require changes to networking, e.g. Security Groups, Elastic IP's and Elastic Load Balancers. Also note that Tags should be captured and verified / re-applied as well.

If you do complete progress with this look at using CloudFormation (https://aws.amazon.com/cloudformation) to provision the new instances so they can be managed as code going forward, which will make future migrations / updates easier.