By FirmDocs · Updated July 2026 · 6-minute read

Can Ontario lawyers use ChatGPT with client files?

Short answer: not the public version — but yes, with AI that keeps the files inside your office.

Every factual claim below is footnoted to a source you can open — and each source link jumps to and highlights the exact passage on the original page.

What the confidentiality rule requires

Rule 3.3-1 of the Law Society of Ontario's Rules of Professional Conduct requires a lawyer to "hold in strict confidence all information concerning the business and affairs of the client acquired in the course of the professional relationship."^[1] The duty is broad: it covers everything you learn about the matter, not just what's marked privileged, and it applies whether or not disclosure would actually harm the client.

Two things follow that matter for AI. First, a confidentiality breach doesn't require anything to be published — disclosing client information to a third party, such as an AI vendor's servers, without the client's consent is already the problem. Second, using new technology doesn't lower the bar: the commentary to the competence rule expects a lawyer to develop an understanding of the technology they use and "the benefits and risks associated with relevant technology, recognizing the lawyer's duty to protect confidential information."^[2]

Why public ChatGPT is the problem

When you paste or upload something into the public version of ChatGPT, that text leaves your office and lands on a third party's infrastructure. In practical terms:

• It's processed and often stored on servers you don't own — frequently outside Canada, under another country's laws.
• On the consumer tiers, your inputs can be used to help improve the model. OpenAI's own policy says it "may use Content you provide us to improve our Services, for example to train the models that power ChatGPT," unless you opt out.^[3]
• You can't audit what happens to it, and you can't guarantee it's truly deleted.
• Handing privileged material to an outside party can complicate — or undercut — the confidentiality you're supposed to protect.
• If the provider is breached, your client's information is part of that breach.

None of that is a knock on the technology. It's just the wrong place to put a client's file.

What about ChatGPT Enterprise, Teams, or the API?

The business tiers help. They promise not to train on your inputs, add administrative controls, and offer data-handling commitments — which meaningfully lowers the risk compared to the free tool. But the documents still leave the building for someone else's cloud, where they're subject to that vendor's security, staff, outages, and any lawful-access requests in the country the data sits in.

Whether that residual risk is acceptable is a judgment each firm has to make and be able to justify — ideally in writing, and with the client's informed consent where appropriate. Plenty of firms look at it and decide the cleaner answer is simpler: don't send the client's files out at all.

The approach that avoids the question entirely

If the AI runs where the files already live, the confidentiality question mostly disappears. That's the idea behind FirmDocs: a small, dedicated machine that sits inside your office and reads your matter documents right there. Nothing is sent to the cloud, nothing is transmitted to us, and it keeps working even if you unplug the internet.

You still get what people want from ChatGPT — ask a question in plain English, get an answer — but every answer cites the exact document and page it came from, and the material never leaves your custody. It's the same benefit, without the part that conflicts with your obligations.

So — can Ontario lawyers use ChatGPT with client files?

With the public tool and identifiable client material: treat it as off-limits. With private, on-premise AI that keeps the files inside your office: yes — and it's how you get the productivity without the confidentiality problem. As always, confirm your own approach against the Law Society's current guidance and your firm's risk tolerance.

AI can make mistakes — always check an answer against the source it cites. The quoted passages here are verbatim from the linked sources, and each link opens the original and highlights the passage. This article is general information, not legal or compliance advice, and does not create a lawyer–client relationship. For your own obligations, consult the Law Society of Ontario's resources or your practice advisor.