Does Incorporating Save Tax in Ontario?

"Should I incorporate?" is one of the most common questions Ontario business owners ask their lawyers and accountants. The short answer is: it depends — but the tax angle is often what makes or breaks the decision.

Incorporation tax benefits in Ontario are real, but they are not automatic and they are not permanent. They stem primarily from the difference between the corporate tax rate and the personal tax rate, and from your ability to control when and how you take money out of the business. Get the structure right and incorporating can meaningfully accelerate wealth accumulation. Get it wrong — or incorporate before you are ready — and you will spend more on compliance than you save on tax.

This article explains the core concepts. For the current rates and your specific numbers, you will need to work with an accountant. For the legal structure itself, that's where we come in.

The Core Tax Benefit: Deferral

When you run a business as a sole proprietor, every dollar of profit flows directly onto your personal tax return and is taxed at your marginal rate in the year it is earned. At higher income levels, Ontario's combined federal-provincial personal tax rates are significantly higher than the corporate rate on small business income.

A corporation is a separate legal entity that pays its own tax. The key insight is that income left inside the corporation is taxed at the corporate rate — which, for qualifying small businesses, is substantially lower than top personal rates (verify current rates with the CRA or your accountant, as they change). The gap between what the corporation paid and what you would have paid personally is money that stays inside the corporation and can be reinvested.

This is called tax deferral. You have not permanently escaped tax — when you eventually pull money out of the corporation as a salary or dividend, you pay personal tax on it. But the longer you can leave profits inside the corporation and deploy them, the more the deferral compounds.

Tax deferral is most valuable to business owners who:

• Do not need all of their business income personally each year
• Have surplus cash they want to invest or reinvest
• Are in high personal marginal tax brackets

If you need every dollar the business earns to live on, the deferral benefit largely disappears.

The Small Business Deduction

The reduced corporate rate on active business income is made possible primarily by the small business deduction (SBD). This deduction reduces the federal corporate tax rate on the first portion of active Canadian business income earned by a Canadian-controlled private corporation (CCPC). The provinces, including Ontario, have their own parallel low-rate on small business income.

The SBD applies up to what is called the small business limit — a threshold of active business income above which the full corporate rate applies instead of the reduced rate. This limit is set federally and is subject to change; always verify the current figure with your accountant.

There are also rules that can reduce the small business limit, including rules related to passive investment income earned inside the corporation (more on this below). For a fuller explanation of the SBD mechanics, see our companion article on the small business deduction in Canada.

Salary vs. Dividends: How You Pay Yourself

Once money is inside a corporation, the business owner can pay themselves in two main ways:

Salary

A salary paid to you is deductible to the corporation (reducing corporate tax) and taxable to you personally. You pay CPP contributions on salary income. Salary creates RRSP contribution room, which dividends do not. You can also pay a reasonable salary to a family member who works in the business, though the rules require genuine work at fair market compensation.

Dividends

Dividends are paid from after-tax corporate profits. They are taxed in your hands, but at a lower personal rate than salary because of the dividend tax credit — a mechanism designed to account for the fact that the corporation has already paid tax on the income before distributing it. This integration is imperfect, but the general principle is that the combined corporate-plus-personal tax on income distributed as a dividend should roughly equal the personal tax you would have paid if the income came directly to you.

The Optimal Mix

Most incorporated business owners use a combination of salary and dividends. The right mix depends on your personal income needs, your marginal tax bracket, whether you want RRSP room, and your CPP strategy. An accountant can model this for you annually.

Income Splitting and TOSI

Prior to 2018, a common tax-planning technique was to pay dividends to family members (a spouse, adult children, or a family trust holding shares) who were in lower tax brackets, thereby spreading income across multiple taxpayers and reducing the overall family tax bill. This is called income splitting.

The federal government significantly restricted this strategy by introducing the Tax on Split Income (TOSI) rules. Under these rules, income from a private corporation paid to a family member is taxed at the highest marginal personal rate unless the family member meets specific exemptions — primarily that they made genuine contributions to the business. Simply owning shares and receiving dividends is no longer enough to benefit from a lower rate.

TOSI is complex. Do not assume a family shareholding structure you set up years ago is still as tax-efficient as it once was. An accountant and a lawyer can review your current structure.

The Passive Income Grind

There is a further consideration for corporations that accumulate significant investment income (passive income): interest, rent, and portfolio investment returns earned inside the corporation. The federal rules include a passive income grind on the small business limit — as passive income inside the corporation exceeds a threshold (as of writing, verify the current figure), the SBD limit is progressively reduced, increasing the corporate rate on active business income.

The upshot: using a corporation as a personal investment vehicle for large amounts of passive income can erode the SBD benefit. This is an advanced planning issue that your accountant should model before you invest large sums inside a corporation.

When Incorporation Is NOT Worth It

Incorporation has real costs: legal fees to incorporate, annual corporate tax returns (which cost more than personal returns), potential compliance requirements, and the administrative burden of maintaining a separate corporate account and records. These costs can easily run several thousand dollars per year.

Incorporation typically makes less sense when:

• Your business income is modest and you need it all personally each year
• You are a few years from retirement and the deferral window is short
• Your profession's governing body restricts corporate structures (though professional corporations are available for many regulated professions in Ontario)
• Your business is high-risk and the personal liability shield is the main motivator — that's a legitimate reason, but it's separate from the tax analysis

Frequently asked questions