Consolidated billing without being part of the OU in AWS Organization

Hello,

currently, we have an AWS account A, which is a root account in AWS Organizations with consolidated billing for all account members. Plan: create account B, it's billing joins the billing under account A Organizations and it's other members, but at the same time, it will be independent root account in it's own AWS organizations. So, the accounts A and B are not members of the same Organization, but have linked billing.

Is that doable?

Thanks, Michal