When attempting to change the ownership of an invoice, you may have seen an error message stating "Invalid Owner Change". One thing to check is whether the invoice owner has access to the legal entity or org unit that the invoice is coded into. If they don't have access, you can grant access permission to these users by going into their settings in User Management:
http://support.beanworks.com/system-admin/user-management/how-to-change-a-users-access-to-org-units