Incorporating an orthodontic practice: the DPC, timed around your case book

Why incorporation pays for a specialist practice

The math is the same one that makes incorporation attractive for any Ontario dentist: profit retained inside a Dentistry Professional Corporation is taxed at roughly 12.2% under the combined federal-provincial small business rate, as at the time of writing, against a personal marginal rate that can exceed 53%. For an orthodontist buying into or building a practice with real estate, imaging equipment, and a treatment coordinator's salary on top of clinical staff, that spread compounds every year retained earnings sit inside the corporation rather than flowing out personally.

The honest caveats still apply. A new associate carrying student debt with little left over each month gains mostly compliance cost, not tax advantage, from incorporating early. And a DPC does not touch professional liability — that follows the orthodontist personally regardless of the corporate structure, which is why RCDSO Professional Liability Program coverage still does the real protective work.

Same College, same rules — orthodontists are RCDSO members too

An orthodontist is a dentist with additional specialty certification, regulated by the Royal College of Dental Surgeons of Ontario the same as any general dentist, so the corporation is the same OBCA-incorporated DPC holding a Certificate of Authorization from the College — not a distinct "orthodontic corporation." The naming convention, the restriction to practising dentistry, and the share rules all carry over unchanged.

If you plan to operate a second location, confirm the College's current requirements for each site with your incorporation counsel before signing a lease — location-specific authorization details are worth checking case by case rather than assuming from the first office.

Corporate program accounts start from zero at incorporation. Most orthodontic DPCs need two: the RC account for the annual T2, and the RP account once clinical assistants and a treatment coordinator move onto the corporation's payroll — our orthodontist payroll page covers that cutover. A GST/HST account is the fourth, and it applies to most established orthodontic practices in a way it rarely does for a purely exempt general dental office: because the zero-rated appliance portion of each case fee still counts as a taxable supply toward the $30,000 small-supplier threshold, an active practice generating even a modest allocated appliance revenue crosses that line quickly, and registration stops being optional.

Timing incorporation around your case book

The detail general dental incorporation guides rarely mention: because treatment contracts run 18 to 36 months, a case signed personally before incorporation and a case signed by the DPC after are not interchangeable. Fees earned on a contract entered into before the corporation existed are generally your personal income even if collected afterward, so an orthodontist incorporating mid-career should expect a transition period where both a personal return and the new DPC's first T2 report real revenue from overlapping cases.

We plan the incorporation date around your new-case calendar rather than a calendar quarter, so the cutover is clean: existing contracts wind down on the personal side, new contracts are signed by and payable to the DPC, and the bookkeeping split — covered on our orthodontist bookkeeping page — has one clear line instead of a blended year no one wants to unwind later.

Selling, merging, or bringing on a partner

Non-voting family shares mostly earn their value at a sale rather than during active practice, since dividends to a spouse or adult child generally trip TOSI while you're still working. When DPC shares that qualify as qualified small business corporation shares are eventually sold, each shareholder can claim their own lifetime capital gains exemption, now $1.25 million — but qualification depends on the corporation holding mostly active practice assets in the period leading up to the sale, and a portfolio of retained investments is the usual thing standing in the way.

Consolidators buying orthodontic practices read the minute book and the case-volume trend closely, and a two-orthodontist merger raises the added question of how each partner's active caseload and receivables get valued going in. We keep DPC records sale-ready as part of ongoing incorporation and compliance work, and if either partner trained or holds accounts in the US, that side of the file belongs on our cross-border tax page for orthodontists. See also what a professional corporation is and who can have one for the broader rules behind the DPC.

Source: Royal College of Dental Surgeons of Ontario.