Can I sell my law practice's client files without getting each client's consent first?

No, not as a general matter. Client files belong, in a real sense, to the client, and a lawyer's duty of confidentiality doesn't disappear just because the practice is being sold. A lawyer selling or winding down a practice is generally expected to notify affected clients of the change and give them a genuine choice: consent to their file moving to the successor lawyer or firm, or have it transferred elsewhere (or returned to them) instead.

This is different from other business sales, where "the business" and its records can often be treated as a single asset. A law practice sale needs a client communication and consent process built alongside the purchase agreement, and the buyer needs to understand that it may not actually receive every client relationship the seller currently has, since some clients will choose to go elsewhere.

The Law Society of Ontario has specific expectations about how a practice transition should be handled, including safeguarding client confidentiality and trust obligations throughout. Because getting this wrong can trigger a professional conduct complaint even after the deal closes, working through the notice and consent process with a lawyer experienced in practice transitions, rather than treating it as a standard asset transfer, is the safer approach.