The Dentistry Professional Corporation (DPC): Is It Still Worth It?

For most dentists in Ontario, incorporating is the single most powerful tax deferral tool available. However, many associates and new practice owners ask us: “Is it worth the extra paperwork?”

The answer lies in the Small Business Deduction (SBD).

The Deferral Advantage

As a sole proprietor, your income is taxed at your personal marginal rate, which in Ontario can skyrocket to over 53.53% for high earners.

When you incorporate as a DPC, your practice’s active business income (up to $500,000) is taxed at the combined federal and Ontario small business corporate rate, which is significantly lower (approx. 12.2%).

The Math: If your practice earns $300,000 in net income:

• Personal Tax (Sole Prop): You might pay ~$130,000+ in taxes immediately.

• Corporate Tax (DPC): The corporation pays ~$36,600.

This leaves nearly $100,000 extra inside your corporation. You can use these “pre-personal-tax” dollars to:

• Reinvest in new dental technology (scanners, chairs, X-ray machines).

• Pay down practice loans faster.

• Invest in a corporate investment portfolio (retirement savings).

Note: You only pay personal tax when you withdraw the money as a salary or dividend. The goal is to leave the money you don’t need for daily living inside the corporation.

2. Navigating TOSI (Tax on Split Income) in 2026

Historically, dentists would incorporate and sprinkle dividends to a spouse or adult children to lower the overall family tax bill. The CRA introduced TOSI rules to crack down on this.

In 2026, you cannot simply pay dividends to family members unless they are actively involved in the business.

The “Excluded Business” Exception

To pay dividends to a spouse without triggering the highest tax rate (TOSI), they must generally work an average of 20 hours per week in the practice throughout the year or have met this threshold in five prior years.

What this means for you: If your spouse manages your booking software, handles payroll, or oversees the office administration, you must document their hours. At Apex Accounting, we recommend keeping a detailed log of their contributions. If the CRA audits your practice and finds your spouse’s involvement was “on paper only,” those dividends will be taxed at the highest marginal rate.

The “Reasonableness” Test

Even if they work fewer than 20 hours, you may be able to pay a reasonable salary (not dividends) based on the market rate for the work performed. If you pay a spouse $80,000 to file papers once a month, that will be flagged. If you pay them $45,000 to manage full-time reception duties, that is likely defensible.

3. Capital Gains and Selling Your Practice

One day, you will want to sell your patient list or your entire practice. This is where the Lifetime Capital Gains Exemption (LCGE) becomes your best friend.

As of 2026, the LCGE limit continues to adjust for inflation (approaching $1 million+). This means if you sell the shares of your DPC, the first ~$1 million of capital gain could be tax-free.

The “Purification” Trap: To qualify for the LCGE, your corporation must be a “Qualified Small Business Corporation” (QSBC). A key rule is that 90% of the corporation’s assets must be used for active business at the time of sale.

• The Problem: Many dentists accumulate too much “passive” cash or investments inside their DPC over the years.

• The Risk: If your DPC is holding $500,000 in a stock portfolio, it might be considered “tainted” (not active), and you could lose the tax-free exemption upon sale.

The Apex Solution: We help dentists implement “purification” strategies—moving excess cash out of the DPC into a holding company or family trust well before a sale occurs—to ensure you qualify for the exemption when it’s time to retire.

4. Maximizing Deductions: What Dentists Often Miss

We often see dental practices missing out on valid deductions because they are afraid of an audit, or simply unaware. Here are specific items Ontario dentists should review:

Scientific Research & Experimental Development (SR&ED)

Did you know that some clinical work involving experimental techniques or developing new dental technologies might qualify for SR&ED tax credits? While routine dentistry does not qualify, developing proprietary software or modifying equipment for unique clinical cases might.

Associate Fees & Contracts

If you hire associates, the CRA is looking closely at whether they are true independent contractors or employees.

• Employees: You must pay CPP/EI.

• Contractors: They invoice you.

• The Risk: If your contract restricts them from working elsewhere or dictates their specific hours too rigidly, the CRA may deem them employees. Review your associate agreements annually.

Conventions and Continuing Education (CE)

You can generally deduct the cost of two conventions per year. However, the convention must be related to your business. A “dental conference” held on a cruise ship where the schedule is 90% leisure and 10% learning may be disallowed. Always keep the itinerary and proof of attendance.

Equipment “CCA” (Capital Cost Allowance)

The Immediate Expensing rules have evolved. Ensure you are capitalizing large equipment purchases (like a CEREC machine or panoramic X-ray) correctly to maximize depreciation claims in the years where your income is highest.

5. The Holding Company Strategy

As your practice matures and your DPC accumulates significant savings, it is often wise to set up a secondary corporation: a Holding Company (Holdco).

You can pay tax-free inter-corporate dividends from your Dental Corp (Opco) to your Holding Corp.

• Why do this? It protects your accumulated wealth. If your dental practice is sued (e.g., malpractice or slip-and-fall not fully covered by insurance), assets inside the practice are at risk.

• Asset Protection: By moving cash to the Holdco, those assets are legally separate from the dental practice. This is a critical risk management strategy for established dentists in the GTA.

Conclusion: Proactive vs. Reactive Accounting

The dental industry in Ontario is competitive. With rising overhead costs—staff wages, PPE, and rent—you cannot afford to be inefficient with your taxes.

At Apex Accounting, we understand that you don’t have time to study the Income Tax Act. That’s our job. Whether you are a new associate looking to incorporate or a veteran practice owner planning an exit strategy, we provide the specialized guidance you need.

Are you confident your current accounting structure is saving you money?

Don’t wait until tax season to find out. Contact Apex Accounting & Tax Consulting today for a review of your corporate structure.