What Is Solicitor-Client Privilege and How Do You Protect It in a Digital Practice?

Solicitor-client privilege is one of the most jealously guarded protections in Canadian law. The Supreme Court has called it a principle of fundamental justice. But privilege that took decades to build into the law can be quietly weakened by something as mundane as the software you use to store a client's file.

Here's what privilege actually is, how it differs from your confidentiality duty, and what it takes to protect it in a practice that runs on cloud tools.

Privilege vs. Confidentiality: They're Not the Same Thing

Lawyers often use these terms interchangeably, but they're distinct:

• Confidentiality is your ethical duty under LSO Rule 3.3-1 to hold client information in strict confidence. It's owed to the client and enforced by the Law Society.
• Solicitor-client privilege is a substantive legal protection that shields communications between a lawyer and client (made for the purpose of legal advice) from disclosure — including to courts and opposing parties.

The two are related but independent. You can breach confidentiality without destroying privilege, and privilege can be lost even where you tried to keep something confidential. Understanding both matters, because your tools affect both. (For the confidentiality side specifically, see our breakdown of LSO Rules 3.1-2 and 3.3-1.)

How Privilege Gets Weakened in a Digital Practice

Privilege depends on communications remaining confidential. The moment privileged material is exposed to a third party, you risk arguments that privilege has been waived or never properly maintained. In a digital practice, that exposure usually happens in one of a few ways:

Third-party access. When privileged documents sit on a platform whose operator can access them — for support, for "product improvement," or to train AI models — you've introduced a third party to the communication.

Foreign-government reach. If your provider is a US company, the US CLOUD Act can compel disclosure of your client's data regardless of where it's stored, without a Canadian court's involvement. That's the opposite of the protection privilege is meant to guarantee.

AI training. Feeding privileged documents into a tool that uses your inputs to train its models — as many consumer AI products do — means privileged content becomes part of a system you don't control. This is exactly why pasting client files into ChatGPT is so risky.

Inadvertent disclosure. Overly broad sharing links, files stored in personal accounts, and tools with no access controls all raise the odds of privileged material reaching someone it shouldn't.

What It Takes to Protect Privilege Digitally

Protecting privilege in a modern practice comes down to controlling access and jurisdiction:

1. Store data on Canadian servers, operated under Canadian law, beyond the reach of foreign compelled-disclosure regimes.
2. Have a Data Processing Agreement that contractually restricts how your provider can access and use your data.
3. Use tools that never train on your data — your privileged material must not become part of anyone's model.
4. Keep audit logs so you can show exactly who accessed a privileged document and when.
5. Isolate data per matter so information stays scoped to the file it belongs to, limiting accidental cross-exposure.

None of these are exotic. They're the baseline for any tool that touches privileged material.

A Quick Self-Audit

For each tool in your practice that stores client communications or documents, ask:

• Could the provider access this privileged material, and under what terms?
• Is the provider subject to a foreign disclosure law?
• Is my data used to train anything?
• Can I produce a record of who accessed a given file?

If the answers make you uncomfortable, that tool is a privilege risk — not just a confidentiality one.

The Bottom Line

Privilege is a legal protection you can lose through the back door of bad software choices. Keeping privileged material on Canadian infrastructure you control, under contractual protection, with no third-party training and full access logging, is how you keep that door shut.

Surface is built to protect privileged material by default — Canadian servers, a DPA available on request, no AI training on your files, per-matter isolation, and audit logs of every access. See our full compliance approach.