Informal Opinion Number: 2026-11
Adoption Date: August 3, 2026
Question: Ten years ago, Lawyer A created a declaration of trust for property for a client, Grantor, and named one of Grantor’s children, Child 1, as trustee. Lawyer A also did additional estate planning for Grantor. Five years ago, Lawyer B amended the declaration of trust to add another child of Grantor, Child 2, as a co-trustee with Child 1. Two years ago, Grantor passed away. A dispute arose between the co-trustees as to the property in the declaration of trust, and Child 1 sued Child 2. Lawyer A has been subpoenaed to testify as to Grantor’s intent as to the property in trust, as well as the rest of the estate plan. Would Lawyer A violate any Rules of Professional Conduct if Lawyer A sat for a deposition or testified pursuant to a subpoena at trial in the underlying litigation between Child 1 and Child 2?
Answer: The Rules of Professional Conduct do not prohibit Lawyer A, per se, from testifying during a deposition or at trial pursuant to subpoena in the underlying litigation, however, Rules 4 dash–1.9(c) and 4 dash–1.6 may severely restrict Lawyer A’s ability to testify to relevant issues in the underlying lawsuit. Rule 4 dash–1.9 addresses a lawyer’s duty to former clients. Subsection (c)(2) provides that a lawyer who has formerly represented a client in a matter shall not reveal information relating to the representation except as permitted by the Rules of Professional Conduct. Rule 4 dash–1.6(a), in turn, provides that a lawyer may not reveal information relating to the representation of a client unless the client gives the lawyer informed consent, the disclosure is impliedly authorized to carry out the representation, or the disclosure is permitted by Rule 4 dash–1.6(b).
Rule 4 dash–1.6 survives the death of a client. See Comment [17] to Rule 4 dash–1.6 and Missouri Informal Opinion 990146. The confidentiality provisions of Rule 4 dash–1.6 are much broader than the substantive law issues of attorney-client and work product privileges. Confidentiality covers all information related to the representation, no matter its source.”[1] See Rule 4 dash–1.6, Comment [3].
Thus, Rule 4 dash–1.6 will prohibit Lawyer from revealing information about Grantor’s estate planning unless the disclosure was impliedly authorized, Granter gave informed consent to Lawyer to do so, or one of the Rule 4 dash–1.6(b) exceptions apply.
Informed consent as used in Rule 4 dash–1.6 is defined as the “agreement by a person to a proposed course of conduct after the lawyer has communicated adequate information and explanation about the material risks of and reasonably available alternatives to the proposed course of conduct.” Rule 4 dash–1.0(e).
Rule 4 dash–1.6(b) provides that “[a] lawyer may reveal information relating to the representation of a client to the extent the lawyer reasonably believes necessary: …(4) to comply with other law or a court order.” Determining if there is “other law” that permits disclosure of the Grantor’s confidences is a matter of law and beyond the scope of the Rules of Professional Conduct. Lawyer A should consult Comment [10] to Rule 4 dash–1.6 for additional guidance as to any possible exception at law and use independent professional judgment on this issue.
A subpoena is not enough to require disclosure of client confidences. Rather it must be a court order and Lawyer A must assert “all nonfrivolous claims that the order is not authorized by other law or that the information sought is protected against disclosure by the attorney-client privilege or other applicable law.” Comment [11] to Rule 4 dash–1.6. If the court orders the disclosure of client confidences and an appeal is not sought, Lawyer A may comply with the court’s order. See Comment [11] to Rule 4 dash–1.6; See also Missouri Informal Advisory Opinions 20060004, 20010154, 2017 dash–04, 2026 dash–04, and 2026 dash–06.
In the event that disclosure is permitted by Rule 4 dash–1.6(b), Lawyer A should consult Comments [12] and [13] to Rule 4 dash–1.6 for guidance on ensuring that the disclosure is only to the extent Lawyer A reasonably believes is necessary to accomplish the specified purpose.
[1] Related bodies of law address confidentiality through attorney-client privilege and the work-product doctrine, but interpretations of those principles are matters of law and beyond the scope of the Rules of Professional Conduct. See Rule 4–1.6, Comment [3].
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