Under Rule 1.18, a lawyer who is consulted about a matter by a prospective client, but not retained, is disqualified from representing another client who is adverse to the prospective client in the same or a substantially related matter if the lawyer received from the prospective client “disqualifying information” — i.e. information that could be significantly harmful to the prospective client in the matter. But, if the lawyer “took reasonable measures to avoid exposure to more disqualifying information than was reasonably necessary to determine whether to represent the prospective client,” and the firm takes specified procedural precautions, then the lawyer’s conflict of interest is not imputed to others in the lawyer’s firm.

ABA Formal Opinion No. 510 addresses the “reasonable measures” necessary to avoid the imputation of conflicts to other members of the firm:

Information that relates to “whether to represent the prospective client” includes information relating to (1) whether the lawyer may undertake or conduct the representation (e.g. whether a conflict of interest exists, whether the lawyer can conduct the work competently, whether the prospective client seeks assistance in a crime or fraud, and whether the client seeks to pursue a nonfrivolous goal), and (2) whether the engagement is one the lawyer is willing to accept.

Second, the information sought must be “reasonably necessary” to make this determination. Once a lawyer has sufficient information to decide whether to represent the prospective client, further inquiry may be permissible, but it will no longer be “necessary.” That means once a lawyer has decided there is any basis on which the lawyer would or must decline the representation, stopping inquiry on all subjects would place the lawyer in the best position to avoid potential imputation of a conflict to other lawyers in their firm.

Third, the lawyer must limit the information requested from the prospective client, and should caution the prospective client at the outset of the initial consultation not to volunteer information pertaining to the matter beyond what the lawyer specifically requests.


ABA Formal Opinion No. 510 (March 20, 2024).