Sole proprietorship, partnership, or corporation: choosing your Ontario business structure

Before you sell anything, sign anything, or hire anyone, you make one decision that shapes every other legal question your business will face: what the business is. Ontario gives you three basic forms. Sole proprietorship, partnership, and corporation each split liability, tax, and cost differently, and the right answer depends on your risk, your income, and where the business is headed. Updated for August 2026 with Ontario's new small business tax rate.

A sole proprietorship is the default. Operate under your own legal name and there is nothing to register; operate under any other name and you register that name through the Ontario Business Registry for $60, renewable every five years. Income is reported on your personal tax return, and startup costs are close to zero.

The trade-off is that there is no line between you and the business. Every debt the business takes on is your debt. If a customer sues, they sue you, and your house, savings, and personal assets are all within reach. There is also no tax planning room: every dollar of profit is taxed in your hands at your personal marginal rate the year you earn it, whether you spend it or not.

Carry on business with someone else with a view to profit and Ontario's Partnerships Act says you are in a partnership, whether or not you signed anything. That matters, because the Act fills every gap you leave with default rules: equal shares of profits, equal say in management, and joint liability for partnership debts, including obligations your partner took on without asking you.

A written partnership agreement displaces most of those defaults. It should cover how profits and losses split, who decides what, how a partner exits, what happens on death or disability, and how disputes get resolved. Partners who skip the agreement are trusting the statute to reflect their intentions, and it rarely does. Limited partnerships and limited liability partnerships exist for specific situations, professional firms among them, but the general partnership is the form most small businesses stumble into.

Incorporating creates a legal person separate from you. The corporation signs its own contracts, owns its own assets, and pays its own debts. If the business fails, creditors generally claim against the corporation, not against your home. That protection is the main event, but it is not absolute. Banks and landlords routinely demand personal guarantees from the owners of new corporations, and a guarantee puts you back on the hook for that obligation no matter what the corporate structure says. Directors also carry personal liability for specific corporate failures, unpaid source deductions and HST among them.

The second advantage is tax. A Canadian-controlled private corporation pays the small business rate on its first tranche of active business income. Combined federal and Ontario, that rate was 12.2% when this post was written. Compare that to personal marginal rates that climb above 53% in Ontario, and the gap funds real growth: profits left in the corporation are taxed lightly now, and you pay personal tax only when you take the money out as salary or dividends. If you spend everything the business earns, this deferral is worth little. If the business earns more than you need to live on, it is worth a lot. For a closer look at what incorporation does and does not protect, see our post on personal liability for corporate owners.

The costs are real but modest: $300 to file articles of incorporation online in Ontario, or $200 federally, plus a NUANS name search if you want a named corporation. The ongoing burden is the part founders underestimate. A minute book, annual returns, separate corporate tax filings, and the discipline of keeping corporate money and personal money apart all come with the certificate.

• Start with risk. A business that can hurt someone, damage property, or take on debt should usually incorporate from day one. Construction, food, transport, anything with premises or employees: the liability shield alone justifies it.
• Then look at income. Earning less than you need to live on? The corporation's tax deferral does nothing for you, and a sole proprietorship's simplicity wins. Earning more? The deferral compounds year over year.
• Then look at who else is involved. Two or more owners almost always belong in a corporation with a shareholders' agreement, or at minimum a partnership with a real partnership agreement. The default rules of the Partnerships Act are nobody's actual intentions.
• Losses point the other way. Early losses in a sole proprietorship deduct against your other personal income. Losses trapped in a corporation only offset the corporation's own income, past or future.

Plenty of businesses start as sole proprietorships and incorporate once revenue justifies it. The Income Tax Act lets you roll business assets into a corporation on a tax-deferred basis under section 85, but the rollover needs an accountant, a lawyer, and paperwork done in the right order. Starting simple is a legitimate strategy; just price in the conversion before you assume it is free.

Ontario's 2026 budget made incorporation more attractive. Effective July 1, 2026, the provincial small business rate dropped from 3.2% to 2.2%, for a combined federal-Ontario rate of 11.2%, and the provincial business limit rose from $500,000 to $600,000 of active business income. Corporations with year-ends straddling July 1 apply a blended rate for that year.

Choosing a structure is the first legal decision your business makes, and it touches tax, liability, and every contract that follows. If you are weighing the options, Telesh Law Firm Professional Corp can walk you through what each form means for your situation.

• For businesses
• Cost & fees
• Step-by-step guide

This article is general information, not legal advice, and does not create a solicitor-client relationship. It is current as at its publication date and is not revised as the law changes. For advice on your specific situation, book a consultation or call 416-639-0887.

Written by

Caleesis Telesh

Founder & Principal Lawyer

LL.B. · B.A., York University · Member, Law Society of Ontario

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