Billing for AI-Assisted Legal Work — Does NJ RPC 1.5 Let You Charge What You've Always Charged?

There's a quiet tension building inside NJ small firms that nobody wants to talk about out loud: AI is making lawyers dramatically faster, and most of them are still sending the same bills.

A motion that used to take four hours now takes ninety minutes. A contract review that billed at six-tenths is now done in two. The work product is the same — sometimes better — but the time invested is a fraction of what it was. So what does a New Jersey attorney do with that reality when it's time to invoice?

This isn't a hypothetical. It's a billing ethics problem hiding in plain sight, and NJ RPC 1.5 is the rule that will surface it when things go wrong.

What RPC 1.5 Actually Requires

RPC 1.5(a) prohibits attorneys from collecting a fee that is "clearly excessive" given the circumstances. The rule lists eight factors for evaluating reasonableness — including the time and labor required, the novelty and difficulty of the questions, the skill required to perform the work, and the results obtained.

Notice that "time and labor required" is just one factor among many. That's significant. But courts and disciplinary panels have historically treated time as a central proxy for value in hourly-rate matters. If AI has structurally reduced the time required to perform a task, and you're billing the same number of hours as before — or billing hourly for time an AI spent, not you — you have a problem.

The New Jersey Supreme Court's Committee on the Unauthorized Practice of Law hasn't issued specific AI billing guidance yet. But the ABA's Formal Opinion 512 (2024) flagged the issue nationally: lawyers cannot bill for time spent prompting or correcting AI as if it were high-skill attorney time, and they cannot pass through AI tool costs as a disbursement without disclosure. NJ practitioners should treat that as a leading indicator, not a ceiling.

Three Billing Models — and Where Each One Gets Risky

1. Pure hourly billing. If you're billing by the hour and AI just cut your drafting time in half, you face a binary choice: bill fewer hours honestly, or bill your old hours and potentially misrepresent the time actually spent. The second path is where RPC 1.5 exposure lives — and arguably RPC 8.4(c) (conduct involving dishonesty) isn't far behind. The solution isn't to pad your time; it's to restructure how you price the work.

2. Flat-fee arrangements. Counterintuitively, flat fees become more defensible in an AI environment, not less — provided the fee was reasonable at the time of agreement and the scope is clearly defined. If AI lets you deliver a flat-fee will in 45 minutes instead of two hours, you've improved your margin. That's not an ethics issue. It's smart practice economics. The risk area is misrepresenting scope to justify a flat fee that's disconnected from any reasonable measure of value.

3. Passing AI tool costs to clients. Some firms are experimenting with billing AI subscription costs as a disbursement — similar to how research platform costs were once passed through. NJ's RPC 1.5(a) and related disbursement norms require that pass-through costs be actual, reasonable, and disclosed. If you're using one AI subscription across 40 matters and attempting to bill its full monthly cost to a single client, that's a clear violation. Prorated, disclosed, and agreed-upon in your engagement letter? Far cleaner.

The Disclosure Gap Most NJ Attorneys Are Ignoring

Here's the practical problem: most NJ solo attorneys have engagement letters that say nothing about AI. They don't address whether AI tools will be used, whether AI tool costs will be passed through, or how billing will be calculated for AI-assisted work. That silence creates ambiguity that resolves against the attorney in a fee dispute.

The fix is straightforward. Add a short AI billing clause to your standard engagement letter that:

• Discloses that AI tools may be used to assist in legal work
• Clarifies that all AI-generated work product is reviewed and supervised by a licensed attorney
• States whether AI costs are absorbed by the firm or allocated to the client (and how)
• Confirms that fees are based on value delivered and professional judgment, not raw AI output time

One paragraph. It closes the loop on RPC 1.5, supports your RPC 1.4 communication obligations, and signals to clients that your firm operates with deliberate professionalism.

The Bigger Strategic Question

The attorneys who will win on fees in an AI-augmented market aren't the ones who figure out how to disguise AI time in hourly bills. They're the ones who move toward value-based pricing — scoping matters by complexity and outcome rather than hours — and communicate that value clearly upfront.

AI doesn't just change how fast you work. It changes what "a reasonable fee" means. NJ RPC 1.5 was written for a world where time equaled effort equaled value. That world is ending. Your billing model should reflect where things are heading, not where they've been.

If a client ever files a fee arbitration complaint and your bills show six hours of drafting work that an AI completed in forty minutes, you want to have thought through this already — not during the proceeding.