Professional Corporations in Ontario: What Doctors, Lawyers, and Accountants Need to Know

If you are a regulated professional in Ontario — a physician, lawyer, dentist, accountant, or any number of other designations — you have probably wondered whether incorporating your practice makes sense. The short answer is: it can, and many professionals do. But a professional corporation (PC) in Ontario is not an ordinary business corporation. It sits at the intersection of the Business Corporations Act (Ontario) and the rules of your professional governing body, and both sets of rules apply at the same time. This article walks through what a professional corporation is, who can form one, what the real liability picture looks like, and why tax deferral tends to be the biggest practical benefit.

What Is a Professional Corporation Under the OBCA?

A professional corporation is a corporation incorporated under the Ontario Business Corporations Act (OBCA) that is specifically authorized to practice a regulated profession. The OBCA sets the foundational corporate rules — the same statute that governs all Ontario business corporations — but it carves out a distinct regime for professionals by requiring compliance with the applicable professional legislation and the rules of the governing body.

Think of it as a two-layer structure. At the bottom layer, you have a standard Ontario corporation with shares, directors, and officers. Sitting on top of that, you have the regulatory requirements of your profession, which may restrict who can hold shares, what the corporation can be named, and what the corporation is actually permitted to do.

Which Professions Can Incorporate?

Many regulated professions in Ontario are permitted to use a professional corporation, but the authorization comes from each profession's governing legislation, not from the OBCA alone. Examples include:

• Lawyers and paralegals — governed by the Law Society of Ontario
• Physicians and surgeons — governed by the College of Physicians and Surgeons of Ontario (CPSO)
• Dentists — governed by the Royal College of Dental Surgeons of Ontario
• Chartered Professional Accountants — governed by CPA Ontario
• Engineers — governed by Professional Engineers Ontario
• Optometrists, chiropractors, physiotherapists, and several other regulated health professions

This is not an exhaustive list. If you are unsure whether your profession is authorized to incorporate in Ontario, check directly with your governing body — they will have the most current and profession-specific guidance.

Shareholder Restrictions: Who Can Own Shares?

One of the most important restrictions in any professional corporation is the shareholder rule. In general, shares in a professional corporation may only be held by members of the same profession (or, in some cases, by their immediate family members or holding entities they control). This is quite different from an ordinary corporation, where anyone can be a shareholder.

The exact rules vary by profession. Some governing bodies allow limited family ownership (for income-splitting purposes); others are more restrictive. Before you set up share classes or plan an ownership structure, confirm the current shareholder rules with your regulator. Getting this wrong at the incorporation stage can cause serious compliance headaches later.

Liability: What a PC Does and Does Not Protect

Here is the point that surprises many professionals: a professional corporation does not shield you from personal liability for your own malpractice.

Under the OBCA and the professional statutes, you — the individual professional — remain personally liable for any negligent or wrongful act you commit in the course of providing professional services. If you give bad legal advice, misdiagnose a patient, or make an accounting error that harms a client, the corporation does not stand between you and that claim. Your professional indemnity insurance and your personal assets remain on the line.

What a PC can do is limit your exposure to ordinary business debts — things like a lease, a supplier invoice, or an equipment loan. If the business side of your practice runs into financial trouble, you generally have some protection against those creditors in your capacity as a shareholder. But that is a narrow benefit and one that requires careful structuring; it is not a substitute for adequate professional liability coverage.

The Real Advantage: Tax Deferral and Income Flexibility

The primary reason most Ontario professionals incorporate is tax — specifically, the gap between the corporate tax rate on active business income and the top personal income tax rate. As of writing, the combined federal-provincial corporate rate on the first portion of active business income earned in a Canadian-controlled private corporation (CCPC) is significantly lower than the top personal marginal rate — but these rates change, so verify the current numbers with a CPA before making decisions based on them.

The mechanics work like this:

• Income left in the corporation is taxed at the lower corporate rate, giving you a deferral. The personal tax is paid later, when you draw a salary or dividend.
• Income splitting — paying dividends to eligible family members who are permitted shareholders — can shift income to lower-rate taxpayers. The federal "tax on split income" (TOSI) rules significantly restrict this strategy for adults who are not active in the business; your accountant should model this for your specific situation.
• Retained earnings inside the corporation can be invested, allowing the deferred tax to compound over time before it is drawn out.

A word of caution: the tax planning around a professional corporation is genuinely complex. The interaction between TOSI, the small business deduction, passive income rules, and your own compensation mix is not something to improvise. Work with a CPA who advises professionals before you incorporate, not after.

Getting Approval and Choosing a Name

Incorporating a professional corporation in Ontario is a two-step process:

1. Get approval from your governing body. Most regulators require you to apply for and receive authorization before (or concurrently with) incorporation. They will confirm that you are in good standing and that your proposed structure complies with the professional rules.
2. Incorporate under the OBCA. Once you have (or are obtaining) the regulator's approval, the corporation is incorporated at Ontario's corporate registry.

On naming: professional corporations are typically required to include the words "Professional Corporation" (or the abbreviation "Prof. Corp.") in the legal name. Your governing body may have additional naming rules — for example, the Law Society of Ontario has rules about firm name advertising. Check before you commit to a name.

One administrative note: since 2021, the OBCA no longer requires that a majority of directors be Canadian residents. This change has simplified planning for professionals with cross-border situations, though other rules (such as federal income tax residency) still apply.

Frequently asked questions