Justin, a member, has been in public practice for 25 years. His firm does bookkeeping and financial statements for approximately 50 business clients and prepares approximately 75 business tax returns and 200 personal tax returns. Justin's firm has never had a malpractice claim. Justin is contemplating retirement and wants to sell his accounting practice. He has hired a professional practice sales firm to help him identify potential buyers and assist in the practice sale. What is Justin's firm required to do to protect its client's confidential information in this type of situation?