Lawyers and accountants have always had an uneasy relationship, and that tension extends to the attorney-client privilege context. Accountants can either be inside or outside privilege protection.
In Perino v. Edible Arrangements International, Inc., the court held that a lawyer had properly "engaged an outside forensic accounting firm to assist with the investigation" of plaintiff's activities — meaning that related communications deserved privilege protection. Civ. No. 3:13CV1411 (JBA), 2015 U.S. Dist. LEXIS 39131, at *23 (D. Conn. Mar. 27, 2015). However, ten days earlier, another court addressed the implications of a trade association disclosing privileged communications to its accountant. Kan. Tag-Along Action Only Associated Wholesale Grocers, Inc. v. United Potato Growers of Am., Inc. (In re Fresh & Process Potatoes Antitrust Litig.), Case Nos. 4:10-md-2186-BLW-CWD & 4:13:cv-00251-BLW, 2015 U.S. Dist. LEXIS 33577 (D. Idaho Mar. 17, 2015). That court bluntly stated that the privileged "information was freely shared with [the association's] accountants, and therefore the privilege was waived because it was shared with third parties." Id. at *33.
Accountants normally fall outside privilege protection, unless they legitimately assist lawyers in providing legal advice. On the other hand, disclosing work product to an accountant normally does not waive that more robust protection. Ironically, even an accountant who is outside privilege protection normally can create protected work product — as a client "representative."