Conflicts: Former Clients, Imputation, and Business Transactions

A lawyer's duties to a client do not evaporate when the representation ends; two duties survive indefinitely — the duty of confidentiality and a residual duty of loyalty captured by Rule 1.9. California Rule 1.9 and ABA Model Rule 1.9 both provide that a lawyer who formerly represented a client in a matter shall not thereafter represent another person in the SAME or a SUBSTANTIALLY RELATED matter in which that person's interests are materially adverse to the former client, unless the former client gives informed consent — in California, informed WRITTEN consent. The doctrinal engine is the SUBSTANTIAL-RELATIONSHIP test.

Two matters are substantially related if they involve the same transaction or legal dispute, or if there is otherwise a substantial risk that confidential factual information that would normally have been obtained in the prior representation would materially advance the position of the new client in the subsequent matter. The court does not require the former client to prove what confidences were actually shared — that would force disclosure of the very secrets the rule protects. Instead, the inquiry is whether the nature of the prior work makes it reasonable to infer that relevant confidences would have been imparted.

If the matters are substantially related and the new client's interests are materially adverse, the lawyer is disqualified absent the former client's informed written consent. Rule 1.9 also independently bars the lawyer from USING information relating to the former representation to the former client's disadvantage, or REVEALING it, except as the rules otherwise permit.

Conflicts are not confined to the individual lawyer. California Rule 1.10 and ABA Model Rule 1.10 impute one lawyer's conflict to every other lawyer in the same firm: while lawyers are associated in a firm, none of them may knowingly represent a client when any one of them practicing alone would be prohibited by Rules 1.7 or 1.9. This vicarious-disqualification principle reflects the reality that lawyers in a firm share information, files, and economic incentives. The central qualifier is the ethical SCREEN (sometimes called a 'Chinese wall').

When a lawyer moves from one firm to another and the lawyer acquired protected information at the old firm that would conflict the new firm out of a matter, both California Rule 1.10 and the ABA Model Rules permit the new firm to avoid imputed disqualification by timely SCREENING the personally-prohibited lawyer from any participation in the matter, ensuring that lawyer is apportioned no part of the fee from the matter, and giving prompt written notice to any affected former client so that compliance can be monitored.

California has long recognized screening in the lateral-hire and government-lawyer contexts, and the renumbered Rule 1.10 codifies screening procedures. The screen must be erected promptly — before the conflicted lawyer can share information — and must include physical, electronic, and procedural barriers. A defective or late screen does not cure imputed disqualification.

Imputation also reaches former-client conflicts when a lawyer leaves a firm: the firm is no longer barred from a matter adverse to the departed lawyer's former client unless the matter is the same or substantially related and a remaining lawyer retains protected information about it.

Lawyers who move between government service and private practice face a specialized conflicts regime in California Rule 1.11 and ABA Model Rule 1.11. A FORMER government lawyer is subject to Rules 1.9(c) (confidentiality and use of information) and, in addition, may NOT represent a private client in connection with a matter in which the lawyer PARTICIPATED PERSONALLY AND SUBSTANTIALLY as a public officer or employee, unless the appropriate government agency gives its informed written consent. 'Personal and substantial' participation is a higher bar than mere awareness — it means the lawyer was actively and directly involved.

When such a former government lawyer is personally disqualified, the lawyer's new firm may still undertake the representation if the disqualified lawyer is timely SCREENED from participation, receives NO part of the fee from the matter, and the appropriate government agency receives prompt written notice. This 'screen plus no fee plus notice' mechanism allows firms to hire former government lawyers without being disqualified en masse.

The rule runs the other direction too: a CURRENT government lawyer may not participate in a matter in which the lawyer participated personally and substantially while in private practice, and must observe Rules 1.7 and 1.9. Rule 1.11 also restricts a former government lawyer from using confidential government information about a person, acquired while in government service, to that person's material disadvantage in private practice. The policy is to prevent both the appearance and the reality of lawyers exploiting public office for private gain, while not making former public servants unemployable.

A person who consults a lawyer about possibly forming a relationship is a PROSPECTIVE client, protected by California Rule 1.18 and ABA Model Rule 1.18 even if no engagement ever results. The lawyer who has had such a consultation may not use or reveal information learned in the consultation, subject to the same protections as a former client under Rule 1.9. More consequentially, the lawyer may be DISQUALIFIED: a lawyer who received information from a prospective client that could be significantly harmful to that person in a matter may not represent a client with materially adverse interests in the same or a substantially related matter.

Crucially, this personal disqualification is IMPUTED to the firm — but the firm can avoid imputed disqualification in two ways: by obtaining informed written consent from both the affected client and the prospective client, OR by showing that the disqualified lawyer took reasonable measures to AVOID exposure to more disqualifying information than was reasonably necessary to determine whether to represent the prospective client, and then timely screening the disqualified lawyer (with no fee from the matter) and giving written notice to the prospective client.

The practical lesson is to limit the intake interview: a lawyer doing an initial consult should gather only enough to run a conflicts check and decide whether to take the matter, because the more confidential detail the lawyer absorbs, the greater the risk of disqualification. Throughout all of these former-client, imputation, government, and prospective-client rules, California's narrower confidentiality regime (Section 6068(e) and Rule 1.6) supplies the background obligation: the lawyer must guard the protected information at every peril, which is why screening, no-fee, and notice requirements exist to keep information walled off.

Conflict Rules Beyond Current Clients

Exam Hooks

• Rule 1.9 hinges on 'same or substantially related' + 'materially adverse.'
• Substantial relationship = substantial risk prior confidences would advance the new client.
• Screening (timely + no fee + written notice) can rebut imputation in lateral & government moves.
• Rule 1.11 disqualifies on PERSONAL AND SUBSTANTIAL government participation.
• Limit the intake interview — Rule 1.18 disqualification grows with information absorbed.