Dentistry professional corporation in Ontario: when it is worth it

If you are moving from associate to owner, incorporation stops being a tax question and becomes a purchase question. That is the moment most Ontario dentists should decide.

When does a dentistry professional corporation earn its keep?

The corporate rate on the first $500,000 of active business income is a combined federal and Ontario 11.7 per cent for a 2026 calendar year end. That blends 12.2 per cent on income earned to 30 June 2026 with 11.2 per cent after it, because Ontario's lower rate drops from 3.2 per cent to 2.2 per cent on 1 July 2026 (Canada Revenue Agency; Ontario Ministry of Finance). The top personal marginal rate in Ontario is 53.53 per cent. That is what the next dollar costs past $220,000 of taxable income, not what a whole income pays.

That spread only helps money you keep. Integration means income routed through the corporation and paid straight out to you costs roughly what it would have cost personally.

An associate on a 40 per cent production split who nets $180,000 and spends $175,000 of it has no surplus to shelter. An owner clearing $450,000 from a two-chair practice who lives on $200,000 does.

What does RCDSO require?

A dentistry professional corporation needs a certificate of authorization from the Royal College of Dental Surgeons of Ontario.

The application fee is $750 and is non-refundable. A revised certificate, which you need when the corporate name or the shareholders change, costs $150. Every certificate expires on 31 August regardless of when it was first issued, and a certificate that is not renewed before that date is revoked effective 1 September for failure to comply with renewal requirements (RCDSO).

Put 31 August in the same place you keep your registration renewal. A revoked certificate is a practice problem, not just a paperwork problem.

Who can hold shares?

Voting shares of a dentistry professional corporation may only be held by dentists who are members of the College. Non-voting shares may be held by a member of the College, by a family member of a voting dentist shareholder, meaning a spouse, child or parent, or in trust for one or more minor children of a voting dentist shareholder as beneficiaries (RCDSO).

A holding company cannot sit above the professional corporation and hold its shares. If a planner or a lawyer proposes one, ask them to show you the College rule that permits it.

Non-voting family shares are also not a free income-splitting tool. The tax on split income rules apply the top marginal rate to dividends paid to a related adult unless that person meets an exception, such as being actively engaged in the business on a regular, continuous and substantial basis, or being 25 or older and holding at least 10 per cent of the votes and value of a corporation that earns less than 90 per cent of its income from services (Canada Revenue Agency). Dental practices are service businesses, so that last exception rarely applies.

Associate or owner: the split that matters

The last row is the one associates underestimate. A T2 return, corporate bookkeeping and payroll or dividend slips cost the same whether the corporation shelters $20,000 or $200,000.

What does the structure cost to run?

Budget for four recurring items: the RCDSO renewal, a T2 corporate return, corporate bookkeeping, and either payroll remittances if you take salary or T5 slips if you take dividends. Ask your accountant for their fee on the T2 and the bookkeeping before you incorporate, because in borderline cases that quote decides the question more cleanly than any tax rate does.

There is also a cost that does not appear on an invoice. Money inside the corporation is not yours until you declare it out, and drawing it out is a decision you have to make every year with a professional. Some owners find that useful discipline. Others find it friction. Both reactions are legitimate, and it is worth being honest about which one you are before you file articles of incorporation.

What the Canada Dental Care Plan changes

Practice income mix is shifting. The Canada Dental Care Plan now covers eligible residents without private dental insurance, and for many general practices that has changed both patient volume and the fee schedule applied to a meaningful share of production (Health Canada).

For incorporation the effect is indirect but real: it changes the revenue forecast a valuator uses, and it changes how confident you should be about the surplus you are planning to shelter. Use two years of actual production, not a projection, when you decide.

Dentistry professional corporation (DPC)

An Ontario corporation authorised by RCDSO to practise dentistry, owned under the College's share ownership rules.

Certificate of authorization

The RCDSO document permitting the corporation to practise. It expires every 31 August and must be renewed.

Non-voting share

A share carrying dividend rights but no vote. Family members of a voting dentist shareholder may hold these.

TOSI

Tax on split income. Applies the top marginal rate to dividends paid to related family members unless a specific exception is met.

LCGE

Lifetime capital gains exemption, $1,275,000 for 2026, available on the sale of qualifying small business corporation shares. Indexation resumed in 2026 from the $1,250,000 base.

Run your own figures in the salary vs. dividends calculator before you commit to a remuneration pattern, and look at the corporate vs. personal investing calculator if the plan is to build a retirement fund inside the corporation.

What to bring to a 20-minute review

Bring two years of production figures, your associate agreement or purchase letter of intent, and your accountant's quote for corporate compliance. If you already hold a certificate, bring its renewal date and your current share register. We will tell you whether the corporation is doing anything for you this year, and what would have to change for it to.

Book a 20-minute review