Is AI-Assisted Billing Ethical? What ABA 512 Says
Here's a question that didn't exist a few years ago. An AI tool drafts your pleading in a few minutes, when the same job used to eat the better part of an afternoon. The pleading gets filed either way. So what goes on the bill, the minutes or the afternoon?
The bar has actually answered this one. In July 2024, the ABA's Standing Committee on Ethics and Professional Responsibility issued Formal Opinion 512, the ABA's first comprehensive ethics guidance on lawyers using generative AI. Much of the early commentary chased the confidentiality sections, which are important. For anyone billing by the hour, though, the fee holdings are the part that changes daily practice, and they're shorter and plainer than most lawyers expect.
The short answer
Using generative AI is not the ethics problem. The opinion takes for granted that lawyers will use these tools, much the way they use research databases. What it goes after is one specific billing move: charging a client for hours the work no longer takes.
Bill by the hour, let AI turn a three-hour task into fifteen minutes, and you bill the fifteen minutes. The savings belong to the client, not the timesheet. Nearly everything else in the fee discussion is a footnote to that.
What Opinion 512 actually says about fees
Hourly billing is where the opinion gets most concrete, so start there. Say the drafting took fifteen minutes with the tool's help, and checking its work took another twenty. Bill the thirty-five minutes, all of it real work. What you can't bill is the two or three hours the pleading used to take by hand. Actual time is what the client owes, and using a faster tool doesn't change what actual means.
Flat fees follow the same logic from a different angle. Model Rule 1.5 requires any fee to be reasonable, and a fixed fee priced for an afternoon of work gets harder to defend once the tool reliably finishes the job before lunch. The opinion stops short of demanding a refund on every efficiency gain. It just puts reasonableness back on the table, which for some standardized work is uncomfortable enough.
Two smaller holdings catch firms off guard. You cannot bill a client for time spent learning a general-purpose AI tool; that is your own professional development, like learning a new research database (it can be different if a specific client asks you to use a specific tool). And the direct cost of an AI tool passes through to a client only if you disclose it in advance. General overhead cannot be marked up. You can recover a direct, disclosed cost, but never a markup on your software budget.
Why actual-time records matter more when AI speeds work up
For any hourly firm, there is a quiet consequence in this: once AI speeds the work up, actual time becomes a ceiling you have to prove you stayed under, and that time is now smaller and harder to reconstruct later.
For years the bigger worry ran the other way. Lawyers lose 5 to 15% of billable time to the small tasks nobody stops to record, and that has not gone away. Opinion 512 adds a matching worry on the other side: over-billing by habit, writing down the hours a task used to take because that is still what your gut expects. Writing down the honest number, and keeping a record that proves it, is the discipline billing for AI-assisted work comes down to.
The firms with the easiest time here capture what actually happened as it happens instead of rebuilding a week from memory on Friday. A contemporaneous record of real minutes is the cleanest evidence a bill reflects actual time.
Where passive timekeeping fits the opinion
This is the division of labor Opinion 512 keeps returning to: AI does the drafting, a lawyer supervises the result. Passive timekeeping fits that shape almost exactly.
Ajax, the tool we build, records billable work as it happens on the lawyer's screen and through email, calendar, and phone connections, then drafts time entries from what it saw. Because capture is contemporaneous, the minutes on each draft reflect the time the work actually took, not an estimate written days later. And nothing reaches a client on its own: every entry stays a private draft until the lawyer reviews it, edits anything wrong, and releases it into the billing system.
The limit is worth saying out loud, because it's exactly what the opinion is about: an AI-drafted time entry is still an AI draft, and it needs a lawyer's eyes before it goes out, the same as an AI-drafted pleading does. The software puts an accurate, reviewable entry in front of you in seconds; checking it and owning it is the job Opinion 512 won't let any tool take. That's the pattern the opinion expects for any AI-assisted legal work: the machine drafts, the lawyer decides.
The rest of Opinion 512, briefly
Billing is one corner of the opinion. The rest covers competence, confidentiality, communication, and supervision. On competence: verify what the tool produced, because these tools are confidently wrong just often enough to hurt you. Confidentiality is the one with a concrete checklist: before you put client information into a tool that trains on its inputs, the opinion expects informed client consent, which in practice means demanding no-training terms and encryption from any vendor that touches client data. Communication means telling clients about your use of AI when the engagement, their guidelines, or the nature of the use calls for it. Supervision means a lawyer stays responsible for whatever the AI produced.
Keep one thing in mind before you act on any of this. This article summarizes Opinion 512; it is not ethics advice. Read the opinion in full and talk to your firm's ethics counsel first. The ABA's announcement of Opinion 512 is a fair place to start, and several state bars have issued their own guidance too.
FAQ
Does ABA Opinion 512 ban billing for AI-assisted work?
No. The opinion requires lawyers to bill actual time, nothing more exotic than that. Finish faster with AI's help and you bill what you really spent, review included, not the hours the job once took.
Can lawyers bill time spent reviewing AI output?
Yes. Reviewing and correcting an AI-generated draft is real legal work, and Opinion 512 treats that review time as billable. What you cannot bill is the time the tool saved you.
Does passive time tracking comply with Opinion 512?
It fits what the opinion asks of billing: the record reflects the time work actually took, and a lawyer reviews every entry before anything is billed. The drafts come from software. The responsibility for what gets released doesn't, and it stays with the lawyer.
Do lawyers have to tell clients they use AI?
Sometimes, and the opinion declines to make it simple. Disclosure falls under the duty to communicate, so it turns on the engagement, the client's guidelines, and what the tool is actually doing on the matter. Some uses call for telling the client and some don't, and your ethics counsel is a better judge of which is which than any blog post, ours included.
Real minutes, recorded as they happen, waiting on your review before anything bills: if that's the record you want behind your invoices, book a demo and see it on your own work.
