Short answer: there is no national rule that says you must announce AI on every engagement letter. ABA Formal Opinion 512 (July 29, 2024) treats disclosure as a facts-and-circumstances question under Model Rule 1.4. You still have to be competent, keep confidences, bill honestly, and tell the truth when the client asks. Your state bar may be stricter. Read that one too.
This is a different question from where the files live. Confidentiality is about what the tool can see. Disclosure is about what the client is entitled to know.
When disclosure is required
Opinion 512 is plain on a few points:
- The client asks. If they ask whether you use generative AI, you answer. Evasions are not a strategy.
- Your engagement terms already require it. If the letter or retainer says you will disclose technology like this, you follow the letter you wrote.
- The tool is material to the representation. If a system will process nonpublic client information, or if it will do work the client would reasonably want a say in, Rule 1.4 points toward a conversation so the client can make informed decisions.
Informed consent under Rule 1.6 is the sharp edge. You cannot put confidential client information into a public or training-retention tool without that consent. Explaining the risk is, by definition, disclosing the use.
When it usually is not
Spell-check, a research database, and routine clerical tools that do not swallow the file are not, on the opinion's own terms, a special AI disclosure event. The opinion does not ask you to narrate every piece of software in the office.
What it does ask: understand the tool (Rule 1.1), supervise the output the way you would supervise an associate (Rules 5.1 and 5.3), and do not bill for hours the software erased (Rule 1.5). A chronology drafted in twelve minutes is not a four-hour chronology. The client should not pay for the ghost.
What to put in the engagement letter anyway
A short, boring paragraph beats a surprise later:
- The firm may use assistive tools to gather records, draft, and organize work.
- A lawyer reviews anything that goes to a client, a court, or opposing counsel.
- Confidential information does not go into public tools.
- The client can ask, at any time, which tools touch their matter.
That is not a waiver of competence. It is a clean description of how the work is done.
The questions to ask any vendor before you disclose anything
- Does client data train a model, yours or a subprocessor's?
- Where do the records live during processing, and can the whole thing run on hardware in our office?
- Can we show a client a list of what the system can access on their matter?
- Who owns the drafts and corrections if we stop paying?
If the vendor cannot answer those without a marketing slide, you do not have something you can describe to a client with a straight face.
A realistic first step
Read Opinion 512. Read your state bar's follow-on, if it has one. Then take one closed or nearly closed matter, run the tool you are considering, and have the responsible attorney check the ten facts that would matter in a demand or a hearing. That afternoon tells you what you would actually be disclosing.
If you want help drawing those lines for your firm — with attorneys still on every output — talk with us. If a point tool and a better engagement paragraph are enough, we will say that too.
Related: Client confidentiality when your firm uses AI · our approach for law firms.