Are law firms ethically required to disclose AI use to clients?

The ethical requirement varies by jurisdiction, but the direction is clear. ABA Formal Opinion 512 (published 2024, increasingly referenced in 2026) establishes that lawyers must maintain competence with AI tools and communicate material information to clients — which can include AI use depending on how the AI is used and what the client would reasonably want to know. Several states (including New Hampshire, with SB 640 in 2026) have passed laws requiring written AI disclosure from licensed professionals. California's State Bar issued guidance in 2025 recommending disclosure. The professional liability risk of non-disclosure is now comparable to the compliance risk of disclosure: clients who discover undisclosed AI use are more likely to file bar complaints and malpractice claims than clients who were informed.

What specifically must law firms disclose about AI use to clients?

Based on ABA Opinion 512 and current state guidance, the disclosure should cover: (1) that AI tools are used in the representation — the general fact of AI use; (2) the category of tasks for which AI is used (research, drafting, document review) without requiring disclosure of every specific tool; (3) confirmation that a licensed attorney reviews all AI-assisted work product before delivery; and (4) how client confidential information is protected in AI systems. The disclosure does not require a detailed technical explanation of how the AI works — it requires informed consent at the level a reasonable client would find material.

When should a law firm disclose AI use — at intake or during the matter?

At intake, in the engagement letter or retainer agreement, before work begins on the matter. This is the timing that ABA Opinion 512 contemplates and that NH SB 640 requires. Retroactive disclosure (telling a client after the matter that AI was used) is more likely to generate concern and potentially bar complaints than proactive disclosure at engagement start. The engagement letter is the right document — not a separate disclosure form that clients may not read, and not a verbal disclosure that isn't documented.

Do clients have the right to refuse AI use in their matters?

ABA Opinion 512 indicates that clients may have the right to limit or decline AI use in their representation, depending on the circumstances. As a practical matter: build a client preference question into your intake process ('Our firm uses AI tools for research and drafting; all work is reviewed by an attorney. Do you have any restrictions on AI use in your matter?'). Most clients will not restrict AI use if the disclosure is framed professionally. The handful who do restrict it will appreciate being asked rather than discovering undisclosed use later. Having a documented preference on file protects the firm if a client raises AI use as a concern later.

AI Disclosure Requirements: Law Firms 2026

Published April 18, 2026 · Updated April 2026 · By The Crossing Report · 6 min read

Summary

ABA Formal Opinion 512 establishes competence and communication obligations around AI that amount to a de facto disclosure requirement in most representations
NH SB 640 (2026) creates a statutory disclosure obligation; Tennessee passed companion legislation; additional states are following
Disclosure at engagement start — in the retainer or engagement letter — is the correct timing and document
Professional liability carriers are tracking AI disclosure as a risk management factor; non-disclosure now carries comparable liability risk to disclosure

The Ethical Framework

Law firm AI disclosure requirements sit at the intersection of three sources of authority:

ABA Model Rules of Professional Conduct. Rule 1.1 (Competence) requires lawyers to maintain the legal knowledge and skill necessary for the representation, including keeping abreast of changes in the law and its practice, including the benefits and risks associated with relevant technology. Using AI tools without understanding their risks and limitations may itself be a competence violation. Rule 1.4 (Communication) requires lawyers to keep clients reasonably informed and promptly comply with reasonable requests for information. Whether AI use in a specific representation is information a client would find material — and therefore requires communication — is a judgment call that Opinion 512 provides guidance on.

ABA Formal Opinion 512. Published by the ABA Standing Committee on Ethics and Professional Responsibility, Opinion 512 is the most comprehensive guidance on AI use in legal practice. It addresses confidentiality (Rule 1.6), supervision of AI tools (Rule 5.3), and the competence obligation as it applies to AI. On disclosure, Opinion 512 establishes that AI use that is material to a client's representation warrants communication under Rule 1.4. What is "material" is a facts-and-circumstances inquiry, but using AI to draft significant portions of a brief or contract, conduct legal research that materially influences the matter, or review documents in a way that affects the quality of representation is material.

State AI Disclosure Laws. NH SB 640 (passed Senate March 2026) and Tennessee's companion legislation move AI disclosure from a professional judgment call to a statutory requirement for licensed professionals in those states. The legislative trend indicates additional states will follow.

What the Disclosure Must Cover

Based on ABA Opinion 512 and the NH SB 640 framework, client AI disclosure for law firms should address four elements:

1. The Fact of AI Use

The disclosure must acknowledge that AI tools are used in the representation. This does not require a comprehensive explanation of what AI is or how it works — it requires an honest statement that AI tools assist in legal work.

Example language:

Our firm uses AI-assisted tools to support certain aspects of this representation, including [legal research / document drafting / document review — select applicable]. These tools help us work more efficiently and thoroughly on your matter.

2. Category of AI-Assisted Tasks

Clients are entitled to understand what parts of their representation involve AI. The disclosure should identify the categories of work (research, drafting, document review) without requiring a tool-by-tool breakdown that would be technically burdensome and would create a compliance obligation every time tools change.

3. Attorney Review and Accountability

The disclosure must confirm that a licensed attorney reviews AI output before delivery and bears professional responsibility for all work product. This is the core of the client's informed consent — the AI assists; the attorney is accountable.

Example language:

All work product prepared with AI assistance is reviewed and approved by the responsible attorney, who is accountable for its accuracy and professional quality. Your representation is supervised by a licensed attorney, not by AI.

4. Confidentiality Protection

The disclosure must address how client confidential information is protected when AI tools are used. This is typically the element clients are most concerned about.

Example language:

Client information used in connection with AI-assisted work is processed through enterprise AI systems that operate under data processing agreements prohibiting use of your information for AI model training. We do not use consumer AI tools for any work involving your confidential information.

How to Handle Client AI Use Preferences

ABA Opinion 512 contemplates that clients may have preferences or restrictions on AI use in their matters. Building a preference inquiry into your intake process is the professional approach:

Intake question (add to your standard intake form or engagement letter):

Our firm uses AI tools for legal research, document drafting, and document review. All AI-assisted work is reviewed by the responsible attorney. If you have questions about our AI use practices or preferences regarding AI use in your matter, please note them here or contact us to discuss.

Most clients will not restrict AI use if the disclosure is framed professionally. The ones who do restrict it — typically clients with highly sensitive matters, strong technology concerns, or specific industry requirements — will appreciate being asked. Their documented preference protects the firm.

For clients who do restrict AI use: evaluate whether the restriction is operationally feasible for the type of matter. Some clients may have OCG-based restrictions that require specific documentation; others may have preferences that can be accommodated without changing your substantive workflow significantly.

The Professional Liability Dimension

Professional liability carriers are tracking AI disclosure as a risk management factor in 2026. The claims pattern that is emerging: clients who discover that their attorney used AI tools without disclosure are filing bar complaints and malpractice claims at higher rates than clients who were informed and consented.

The liability math: proactive AI disclosure with proper review documentation creates a defensible record. Reactive disclosure after a client questions the work — or non-disclosure discovered through a third party — creates a professional conduct issue that the claim record cannot rehabilitate.

Your professional liability carrier may have AI disclosure requirements in your policy. Check your policy terms, particularly for any AI-related exclusions or requirements that may have been added at your last renewal.

AI Compliance for CPA and Accounting Firms — Parallel AI disclosure framework for accounting professionals (AICPA standards and state law)
AI Engagement Letter Requirements for Law Firm Compliance — How to structure the engagement letter to satisfy AI disclosure and OCG requirements
AI Professional Liability Insurance for Professional Services — How AI use affects professional liability coverage and what firms need to document

Sources

ABA Standing Committee on Ethics and Professional Responsibility: Formal Opinion 512 (AI in Legal Practice)
ABA Model Rules of Professional Conduct: Rules 1.1, 1.4, 1.6, 5.3
New Hampshire SB 640: Licensed Professional AI Disclosure Act, passed Senate March 2026
Tennessee AI Disclosure Legislation, March 2026
Thomson Reuters Institute: State of the Legal Market 2026

The Crossing Report covers the AI transition for professional services firm owners. The premium tier includes a law firm AI disclosure kit — engagement letter clause, client intake AI preference form, and usage documentation template. Subscribe here →

Client AI Disclosure Requirements for Law Firms: 2026 Guide

Summary

The Ethical Framework

What the Disclosure Must Cover

1. The Fact of AI Use

2. Category of AI-Assisted Tasks

3. Attorney Review and Accountability

4. Confidentiality Protection

How to Handle Client AI Use Preferences

The Professional Liability Dimension

Sources

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