California Code, Financial Code - FIN § 561

No person who has not received a certificate from the commissioner authorizing it to engage in the banking business shall advertise that it is accepting deposits, and issuing notes or certificates therefore, or make use of any office sign, at the place where its business is transacted, having thereon any artificial or corporate name, or other words indicating that the place or office is the place or office of a bank or trust company, that deposits are received there or payments made on checks, or any other form of banking business is transacted, nor shall any person make use of or circulate any letterheads, billheads, blank notes, blank receipts, certificates, or circulars, or any written or printed paper, whatever, having thereon any artificial or corporate name or other words indicating that the business is the business of a bank or trust company, or transact business in a way or manner as to lead the public to believe that its business is that of a bank or trust company, except to the extent expressly authorized by this division.