Incorporating vs. Sole Proprietorship: Tax Comparison in Ontario

The fundamental tax difference between operating as a sole proprietor and through a corporation is the timing and rate at which income is taxed.

Sole proprietor: Business income flows directly to the owner. All net business income is added to the owner's personal income and taxed at their personal marginal rate in the year it is earned — regardless of whether the owner withdraws it. Ontario's top combined federal/provincial marginal rate is approximately 53.53% on income above $246,752 (2025 brackets). There is no deferral mechanism; income is taxed as soon as it is earned.

Corporation: The corporation pays corporate tax on its income, and the shareholder only pays personal tax on amounts drawn out as salary or dividends. The key advantage is the tax rate differential: - The combined federal/Ontario corporate rate for a CCPC with the small business deduction (SBD) is 12.2% on the first $500,000 of active business income - If the shareholder does not need the income personally, earnings retained inside the corporation are only taxed at 12.2% — not at the personal marginal rate

The deferral advantage — illustrated: Suppose an Ontario consultant earns $250,000 of net business income per year and requires only $80,000 for personal living expenses.

As sole proprietor: - All $250,000 is taxed at personal rates: approximately $115,000 in combined federal/Ontario income tax - Net: $135,000 available, of which $80,000 is spent on living, $55,000 is saved personally (in post-tax dollars)

Through a corporation: - Corporation pays 12.2% tax: $30,500 on $250,000 = $219,500 retained after corporate tax - Consultant draws $80,000 salary (corporation deducts this; personal tax owed on salary) - Approximately $170,000 remains in the corporation for reinvestment - Personal tax on $80,000 salary: approximately $17,000 - Total tax paid: $30,500 (corporate) + $17,000 (personal on salary) = $47,500 — versus $115,000 as a sole proprietor

The $67,500 not yet paid in personal tax remains in the corporation, available for reinvestment. This is the deferral advantage.

Prior to 2018, many Ontario small business owners used corporations to 'split income' with family members — paying dividends to adult family shareholders at lower marginal rates, reducing the family's total tax bill. The federal government significantly curtailed this strategy with the Tax on Split Income (TOSI) rules, effective January 1, 2018.

What TOSI does: TOSI applies the highest marginal personal tax rate (~33% federally) to 'split income' received by specified individuals from related businesses, regardless of the recipient's actual marginal rate. This essentially eliminates the tax advantage of paying dividends to family members unless a specific exclusion applies.

TOSI exclusions: Income splitting is still permitted without TOSI applying when: 1. The recipient is age 25 or older and has made a 'reasonable contribution' to the business — generally meaning the recipient is an active employee contributing labour reasonably commensurate with their compensation 2. The recipient is age 25 or older and holds shares of a business that is not a 'professional corporation' and has made a 'meaningful contribution' — assessed based on hours worked, capital contributed, and business risk assumed 3. The business is excluded because it is an arm's-length business (no related-party issue)

TOSI and spouses: Dividends paid to a shareholder-spouse are subject to TOSI unless the spouse is an active contributor to the business. Simply adding a spouse as a shareholder to receive dividends — without genuine work contribution — no longer achieves meaningful income splitting.

Practical implication: Post-TOSI, the income-splitting benefit of incorporation has been substantially reduced for family business owners with non-contributing family members. Tax planning must now focus primarily on the deferral advantage rather than income splitting.

With TOSI limiting income splitting, the primary ongoing tax advantage of operating through a corporation for Ontario business owners is the ability to retain earnings inside the corporation at low corporate rates.

How retained earnings work: After the corporation pays corporate tax at 12.2% on SBD-eligible income, the after-tax amount ($0.878 for every $1 of income) is available inside the corporation. The shareholder does not pay personal tax on this amount until it is drawn out as salary or dividends.

Reinvestment advantage: If the retained earnings are reinvested in the business (equipment, marketing, hiring, product development), the business is effectively using pre-personal-tax dollars for investment. This is more powerful than reinvesting personal savings, which are post-personal-tax.

Example — 20-year investment comparison: Assume $100,000 of annual business income invested at 6% annual return for 20 years: - Sole proprietor invests after-tax income: $100,000 × (1 - 0.50) = $50,000 invested; grows to $160,356 (over 20 years at 6%) - Corporation invests after-corporate-tax income: $100,000 × (1 - 0.122) = $87,800 invested; grows to $281,738 (over 20 years at 6%). Then personal tax is owed on the dividends when paid out — but even after factoring this in, the compounded advantage of starting with $87,800 vs. $50,000 is significant.

The break-even analysis: At what income level does incorporation make sense? A rough rule of thumb: - If you consistently retain $50,000 or more annually inside the corporation, the tax deferral typically exceeds the annual compliance cost of running a corporation (accounting, legal, government fees) — which often runs $3,000–$7,000 per year. - If you consistently draw out all business income as salary to cover living expenses, there is little or no deferral benefit and the administrative cost of the corporation may not be justified.

Once incorporated, a major ongoing tax decision is how to draw income from the corporation — as salary or dividends. See the dedicated entry on Salary vs. Dividends in Canada for a comprehensive analysis. Key points for this comparison:

Salary from the corporation: - Creates RRSP contribution room for the shareholder (18% of prior year earned income, up to the annual RRSP limit) - Deductible by the corporation as a business expense - CPP contributions are required on salary (employer and employee portions — both paid by the owner of a CCPC) - Taxed as employment income at personal marginal rates - Establishes the shareholder as an 'employee' for purposes of EI (though self-employed shareholders are generally not eligible for EI regardless)

Dividends from the corporation: - Paid from after-tax corporate earnings; no additional deduction for the corporation - No CPP contributions required - No RRSP room created - Taxed at personal rates but with the dividend tax credit (which accounts for corporate tax already paid) - For eligible dividends (paid out of income taxed at the general corporate rate), the credit is more generous - For ineligible dividends (paid out of SBD income), the credit is smaller

Optimal mix: Many owner-operators draw a combination of salary and dividends. A common strategy is to draw a salary sufficient to: (a) maximize the RRSP contribution limit, (b) claim business deductions (home office, vehicle, etc.) that require employment income, and (c) meet living expenses — with additional income taken as dividends from retained earnings.

Incorporation is not free. Ontario business owners should weigh the tax benefits against the ongoing administrative obligations and costs:

Incorporation costs: Initial incorporation under the OBCA costs approximately $300 (government fee) plus legal fees of approximately $1,000–$3,000 if using a lawyer. Using online incorporation services costs approximately $500–$1,500 all-in.

Annual compliance costs: - Accounting: Corporations require annual corporate tax returns (T2) and, if earning above certain thresholds, audited or reviewed financial statements. Annual accounting/bookkeeping costs are typically $2,000–$8,000 for a small Ontario corporation. - Ontario annual return: Corporations must file an Annual Return with ServiceOntario (currently $12.50 for provincial corporations). - Corporate minute book maintenance - Payroll administration if paying salary

HST registration: Both incorporated and unincorporated businesses must register for HST if revenues exceed $30,000 in any 12-month period. Incorporation does not change HST obligations.

Liability protection: Unlike the tax deferral benefit (which is quantifiable), the liability protection of incorporation is harder to put a dollar value on. A sole proprietor who is successfully sued faces personal asset exposure; a corporation's shareholders are generally protected (subject to personal guarantees and director liability).

When to NOT incorporate: Operating as a sole proprietor may be preferable when: - Business income is modest and entirely consumed by personal expenses (no retained earnings) - The business is high-risk for losses (losses from a corporation cannot be deducted against personal income; losses from a sole proprietorship can) - The business is expected to wind down within 1–2 years - The owner qualifies for significant personal tax credits (disability, tuition) that require personal income

For Ontario business owners who consistently retain profits and are in the upper-middle or top personal marginal tax brackets, incorporation typically provides a significant tax deferral advantage. The 12.2% CCPC rate vs. 53.53% top personal rate represents a 41-percentage-point deferral on every retained dollar.

However, the deferral advantage only materializes when earnings are actually retained inside the corporation. Owners who draw out all business income as salary gain little from incorporation on a tax basis, and must weigh this against ongoing compliance costs.

The decision to incorporate is ideally made with input from both a tax professional and a corporate lawyer — the tax analysis alone does not capture the full picture (liability protection, investor readiness, succession planning).