Cal. Code Regs. tit. 10, § 10.6009
(b) The services are performed pursuant to a written contract between the subject institution and the customer which provides:
A subject institution may engage in the business of delivering funds and documents from such subject institution to customers of the subject institution and from customers of the subject institution to the subject institution, and no place at which a subject institution delivers funds or documents to a customer of such subject institution or at which a subject institution picks up funds or other documents from a customer of such subject institution for delivery to the subject institution shall on that account be deemed to be an office of the subject institution if: