In law, the Chinese Wall legal term refers to a set of internal procedures a firm uses to block confidential client information from reaching people inside the organization who shouldn’t have it. It is the older name for what most courts and regulators now call an ethical wall, ethical screen, or information barrier. The concept comes up most often when a lawyer who worked on a sensitive matter at one firm joins a new firm that represents the opposing side; a properly built screen can keep the new firm on the case instead of getting the whole office disqualified.
Why the Older Name Is Being Retired
The phrase borrowed its imagery from the Great Wall of China and treated a cultural landmark as shorthand for secrecy. Legal commentators as far back as 1988 called the metaphor both offensive and inaccurate, noting that the Great Wall was built to repel invaders, not to seal two groups off from each other. The UK’s Financial Conduct Authority formally dropped the phrase from its rulebook in 2021. The ABA Model Rules of Professional Conduct never used it; they use “screened” and “screening” as the operative terms.
You will still see the old label in older case law and in some practitioner shorthand. Anyone setting up these procedures today should expect to use “ethical wall,” “ethical screen,” or “information barrier” in filings and compliance documents.
What the Wall Is Built to Solve
The classic trigger is a lateral hire. A lawyer leaves Firm A, where she represented Client X in a contract dispute, and joins Firm B, which represents Client Y on the other side of that same dispute. Under ABA Model Rule 1.9, a lawyer who formerly represented a client cannot later represent someone whose interests are materially adverse to the former client in the same matter or a substantially related one.1American Bar Association. Rule 1.10 – Imputation of Conflicts of Interest – General Rule
That prohibition then spreads. Under ABA Model Rule 1.10, one lawyer’s conflict is “imputed” to every other lawyer in the firm, so if one partner cannot take a case, no one at the firm can either. Screening is the recognized way out. Rule 1.10(a)(2) allows a firm to avoid imputed disqualification when the conflict comes from a lateral lawyer’s work at a prior firm, provided three conditions are met: the conflicted lawyer is promptly screened from any participation in the matter and receives no share of the fee; the affected former client gets written notice describing the screening procedures; and the firm provides ongoing certifications of compliance at reasonable intervals if the former client asks.1American Bar Association. Rule 1.10 – Imputation of Conflicts of Interest – General Rule Not every state has adopted this version. Some impose stricter requirements, and some do not permit screening at all for certain categories of conflicts.
What a Compliant Screen Contains
The ABA defines “screened” as the isolation of a lawyer from any participation in a matter through timely procedures that protect confidential information and prevent other firm personnel from communicating with the screened lawyer about the case.2American Bar Association. Rule 1.0 Terminology – Comment The word “timely” carries real weight. Measures that go up weeks after the lateral hire has already started work are the kind of delay that leads courts to reject the screen entirely.
In practice, an effective screen uses several overlapping measures:
- A written undertaking, signed by the screened lawyer, promising not to communicate with anyone at the firm about the matter or access any related files.
- Firm-wide written notice to every lawyer and staff member on the matter, instructing them not to discuss the case with or around the screened lawyer.
- File restrictions, including locked physical files and blocked electronic credentials in the firm’s document management system.
- Physical separation where possible, with the screened lawyer on a different floor or in a different office from the team handling the case.
- Exclusion of the screened lawyer from any fees earned on the matter.
- Periodic reminders, because people forget.
The comment to Rule 1.0 lists these types of measures as appropriate for reinforcing a screen.2American Bar Association. Rule 1.0 Terminology – Comment Firms that treat screening as a one-time memo rather than an ongoing protocol are the ones that end up in disqualification hearings.
The duty behind all of it is client confidentiality. ABA Model Rule 1.6 bars a lawyer from revealing any information relating to the representation of a client, whatever its source, and even prohibits disclosures that would not themselves reveal protected information but could lead someone else to discover it.3American Bar Association. Rule 1.6 Confidentiality of Information – Comment Modern servers, email archives, and shared network folders can expose information through search results or metadata without anyone deliberately passing along a file, so effective screening now means blocking electronic access at the system level, not just telling people to be careful.
Support Staff Are Covered Too
Paralegals, legal assistants, and law clerks carry confidential information between firms the same way lawyers do. The ABA Model Guidelines for the Utilization of Paralegal Services call for minimum safeguards when a paralegal joins a firm representing the opposing party: the new hire must be cautioned not to disclose anything from the prior employer’s representation, must be instructed not to work on the matter, and the new firm must take reasonable steps to enforce the restriction. Comment 4 to Rule 1.10 says the imputation rule does not automatically prohibit representation when the conflicted person is a paralegal, but the paralegal must ordinarily be screened from personal participation in the matter.4American Bar Association. ABA Model Guidelines for Utilization of Paralegal Services Firms that focus their protocols on attorneys and forget the staff handling the actual documents are leaving an obvious gap.
How Courts Judge Whether the Wall Held
Courts do not take a firm’s word that its screen is working. They look at the specifics, and the results are often unforgiving.
In Cromley v. Board of Education, the Seventh Circuit examined whether a firm’s procedures were strong enough to rebut the presumption that a lateral hire had shared confidential information. The court looked for “specific institutional mechanisms” put in place as soon as the conflict arose: written instructions to every firm member about the screen, locked files with restricted access, password-protected electronic systems, no fee-sharing from the case, and physical separation of the screened lawyer from the team. It also considered firm size, structural divisions, and whether the attorneys had affirmed compliance under oath. Because the firm moved quickly and documented everything, the screen held.5Justia Law. Cromley v Board of Education of Lockport, 17 F3d 1059
The UK’s House of Lords took a stricter view in Prince Jefri Bolkiah v. KPMG. Once a former client shows that the firm holds confidential information and now acts for someone with adverse interests in a related matter, the burden shifts to the firm to prove there is no real risk of disclosure. The risk does not need to be substantial to justify intervention; it need only be more than fanciful. The Lords were skeptical of screens assembled on the fly, stating that an effective information barrier “needs to be an established part of the organisational structure of the firm, not created ad hoc.”6House of Lords. Judgment – Prince Jefri Bolkiah v KPMG (A Firm)
Kassis v. Teacher’s Insurance and Annuity Association shows where a screen simply cannot cure the problem. The new firm hired an attorney named Arnold who had been deeply involved in the opposing side’s case at his prior firm; he had appeared as sole counsel on multiple occasions and was, in the court’s words, “steeped in the files.” A screening agreement went up, but the court found his prior involvement too extensive for any screen to fix. The presumption of disqualification stood, and the entire firm was removed from the case.7Cornell Law School Legal Information Institute. Kassis v Teachers Insurance and Annuity Assoc, 1999 NY Int 0110 When a lawyer was at the center of the prior representation rather than on its periphery, no wall is thick enough.
The Same Idea in Financial Services
The concept extends well beyond law firms. Investment banks, broker-dealers, and other financial institutions use information barriers to keep material nonpublic information from flowing between departments. A bank’s investment banking group may know about a coming merger while its research analysts publish stock recommendations to the public. Without separation, that arrangement invites insider trading.
FINRA Rule 2241 requires broker-dealers to establish and enforce written policies, including information barriers, that insulate research analysts from pressure or oversight by investment banking and sales personnel. It prohibits investment banking staff from reviewing research reports before publication, controlling analyst compensation, or directing analysts to market banking transactions.8FINRA. Research Analysts and Research Reports On the trading side, SEC Rule 10b5-1 provides an affirmative defense for firms that can show the person who made the trading decision was not aware of material nonpublic information and that the firm had reasonable policies and procedures in place to prevent such awareness.9eCFR. 17 CFR 240.10b5-1 – Trading on the Basis of Material Nonpublic Information The mechanics look much like a law firm’s: restricted access to certain floors or systems, monitored communications, and compliance officers tracking who knows what.
What Happens When a Screen Fails
A firm that sets up a screen and gets it wrong faces cascading problems. The most immediate is disqualification. Courts routinely remove firms that put a screen in place too late, left gaps in electronic access, or cannot produce documentation showing the screen was actually followed. Screens that go up after the lateral hire has had time to talk to colleagues about the case are especially vulnerable, because the court has no confidence that confidential information stayed contained.
Disqualification is only the start. Firms face fee forfeiture and may need to return fees already collected and write off unbilled work. Courts have ordered full reimbursement in cases where the conflict was clear. Opposing parties have recovered their own costs, including attorney fees spent litigating the disqualification motion. Reputational damage can fracture client relationships; a firm disqualified for a conflict is one clients think twice about hiring for sensitive work.
Not all of these losses are covered by malpractice insurance. Disciplinary proceedings from bar regulators can bring sanctions against individual lawyers, from reprimands to suspension. The financial exposure is real: documented cases have involved sanctions exceeding a quarter of a million dollars and lawsuits seeking millions in previously paid fees.