Billing for AI-Assisted Discovery in NJ Small Firms Is a Bigger Fee Ethics Trap Than Most Attorneys Realize

Somewhere between running a document review through an AI tool and sending the client a bill, a lot of NJ attorneys are skipping a step that matters quite a bit under RPC 1.5.

The issue isn't whether you can use AI for discovery work. Of course you can. The issue is whether the way you're billing for that work still reflects a reasonable fee once the time it takes has dropped sharply. That question doesn't have an obvious answer, and the bar hasn't handed one to you.

What RPC 1.5 Actually Requires in This Context

RPC 1.5 prohibits collecting an "illegal or clearly excessive fee." The rule lists eight factors for evaluating reasonableness, but two of them become particularly pointed when AI enters the picture: the time and labor required, and the skill needed to perform the service.

If an AI tool cuts your document review time from six hours to forty minutes, billing six hours is a problem. That much is intuitive. The less intuitive part is that the problem doesn't disappear just because you charge for forty minutes, either. If the tool cost you a flat monthly subscription and you've already billed that cost to other clients, charging this client a full hourly rate for the forty minutes may still overstate the real cost of the work, depending on what your fee agreement says and what the client reasonably understood they were paying for.

The New Jersey Law Journal hasn't published a definitive ethics opinion on AI-assisted billing as of mid-2025, and the ACPE hasn't issued specific guidance yet. That gap doesn't protect you. It means you're operating on your own judgment, with RPC 1.5's reasonableness standard as the backstop if a client files a grievance.

The Three Billing Models That Create the Most Risk

Straight hourly on AI-assisted tasks. This is the most common model and the one with the most exposure. If you bill the same hourly rate for work an AI tool compressed from hours into minutes, a fee arbitration panel is going to ask what the client got for those hours. "I spent the time reviewing the AI's output" is a defensible answer only if your engagement letter anticipated that review process and the client understood the scope of it.

Passing through AI tool costs as a disbursement. Some attorneys treat their AI subscription as a pass-through cost, the way they might bill for court filing fees or process servers. This model has a different problem: most AI subscription agreements are enterprise licenses, not per-matter fees. Billing a client $150 for "AI document review" when your monthly tool costs $99 and covers every client matter that month doesn't hold up cleanly under the disbursement framework most NJ engagement letters contemplate.

Value-based fees on AI-assisted matters. This model actually handles the shift better than hourly, because you're pricing the outcome rather than the time. But it requires that your engagement letter frame the fee that way explicitly. A flat fee for "document review in response to plaintiff's discovery requests" transfers the efficiency gain to the client (or not) based on the number you agreed to, not on how long the AI took. That's a cleaner arrangement, and it sidesteps most of the reasonableness tension.

What Your Engagement Letter Probably Doesn't Say

Most NJ small-firm engagement letters were written before AI tools became a real part of the workflow. They describe hourly rates, they define what counts as a disbursement, and they may reference "costs of technology" in a catch-all provision. None of that language was drafted with AI-assisted discovery in mind.

At minimum, your engagement letter should now do three things it probably isn't doing. It should describe how AI tools factor into the fee, whether that means efficiency gains are passed to the client, billed at a reduced rate, or priced into a flat arrangement. It should specify whether AI subscription costs are included in overhead or billed as a matter expense and, if the latter, how that cost is calculated. And it should tell the client that AI may be used in their matter, because the absence of that disclosure creates its own problems under RPC 1.4 independent of the fee question.

A Practical Fix That Doesn't Require Restructuring Everything

You don't have to overhaul your fee model to reduce your exposure here. The simplest near-term step is to add a single AI-billing provision to your standard engagement letter template. Something that says: "Where AI-assisted tools are used to perform legal research, document review, or drafting, fees reflect the attorney's professional judgment and supervision time rather than the elapsed time the tool operated. Any separately billed AI tool costs reflect actual, allocable expenses."

That language won't win a fee dispute on its own, but it closes the transparency gap that makes a grievance easy to file in the first place. Clients who understand what they're paying for, and why, rarely end up in fee arbitration.

The NJ ACPE will likely issue guidance on this eventually. Until it does, your engagement letter is doing more work than it was designed to do.