If you’d like to transfer a domain name from one SiteGround account to another, you will need to raise a support ticket with your request.
Please do so by first logging into your Siteground account and then going to:
User Area > Support > Report Other Billing Issues
Note, the request must be posted from the User Area that currently has the domain name. In the ticket you should specify the domain name that you would like to be moved and the destination account where you would like the domain name to be moved to.
This step is usually completed by the Brandpa staff or a seller.