Small Business Tax in Canada

Canadian small businesses navigate a layered federal-provincial tax framework that differs significantly depending on business structure. Incorporated businesses that qualify as Canadian-Controlled Private Corporations (CCPCs) access preferential corporate rates under the Small Business Deduction (SBD). Unincorporated owners report business net income directly on their personal T1 return. Both structures carry GST/HST and payroll obligations once threshold tests are met. Consulting a qualified Chartered Professional Accountant (CPA) before choosing a structure or filing is strongly recommended.

See the Canada country overview for the full individual income-tax rate framework.

What is the Small Business Deduction and who qualifies?

The Small Business Deduction under Income Tax Act (ITA) section 125 reduces the federal corporate tax rate from 15 percent to 9 percent on the first CAD 500,000 of active business income earned by an eligible CCPC in a tax year. That CAD 500,000 threshold is known as the Business Limit (Canada Revenue Agency, Corporation tax rates, canada.ca, 2025). To claim the SBD, a corporation must be a CCPC throughout the entire tax year: it must be incorporated or resident in Canada, must not be controlled by one or more non-resident persons or public corporations, and must not be listed on a designated stock exchange. The Business Limit is shared among groups of associated corporations under ITA sections 125(2) through 125(7) to prevent profit-fragmentation by splitting income across multiple related entities. Each associated group collectively accesses only one CAD 500,000 limit, allocated by agreement or formula (Canada Revenue Agency, Small Business Deduction rules, canada.ca). Active business income is income from a business other than a specified investment business or a personal services business. Passive rental or investment income does not qualify for the SBD rate.

How do the passive-income clawback and taxable-capital grind reduce the SBD?

Two separate reduction mechanisms can erode or eliminate the Business Limit before it reaches CAD 500,000. First, the passive-income (Adjusted Aggregate Investment Income, or AAII) clawback under ITA section 125(5.1) reduces the Business Limit by CAD 5 for every CAD 1 of AAII above CAD 50,000 in the preceding tax year. The Business Limit is fully eliminated when AAII reaches CAD 150,000. AAII broadly includes portfolio dividends, interest, foreign accrual property income, and taxable capital gains net of allowable capital losses, but excludes dividends from connected corporations (Canada Revenue Agency, Small Business Deduction rules, passive investment income, canada.ca, 2025). Second, the taxable-capital grind under ITA section 125(5.1) phases out the Business Limit for CCPCs and associated corporations whose combined taxable capital employed in Canada falls between CAD 10 million and CAD 50 million. The 2022 federal budget expanded the upper bound from CAD 15 million to CAD 50 million, allowing more capital-intensive businesses to retain at least partial SBD access. At exactly CAD 50 million of combined taxable capital, the Business Limit is fully ground to zero. Both reductions apply independently; the lesser of the two adjusted Business Limits controls.

What are the combined federal-provincial small-business corporate rates?

Provinces levy their own corporate tax on top of the federal rate. Every province and territory maintains a separate small-business rate that layers on the 9 percent federal SBD rate. The table below uses 2025 rates sourced from PwC Worldwide Tax Summaries (Canada Corporate Taxes on Corporate Income, taxsummaries.pwc.com, 2025).

Some provinces have raised their small-business thresholds above the federal CAD 500,000: Nova Scotia applies its rate on the first CAD 700,000 effective April 1, 2025; Prince Edward Island and Saskatchewan both apply their rates on the first CAD 600,000 (PwC, 2025). The general federal corporate rate above the Business Limit is 15 percent; combined federal-provincial general rates range from 23 percent (Alberta) to 31 percent (Prince Edward Island) depending on the province.

How does GST/HST registration work for small businesses?

The Goods and Services Tax and Harmonized Sales Tax (GST/HST) regime under the Excise Tax Act requires registration once a business's total taxable supplies in four consecutive calendar quarters exceed CAD 30,000 (the small-supplier threshold). This threshold applies per supplier, not per transaction, and it includes revenues of associated persons (Canada Revenue Agency, When to register for and start charging GST/HST, canada.ca). A business that crosses the CAD 30,000 threshold in a single calendar quarter must register by the thirtieth day following that quarter. Businesses below the threshold are small suppliers and may voluntarily register, which is often beneficial because voluntary registrants can claim input tax credits (ITCs) on GST/HST paid on business purchases. Certain categories are mandatory registrants regardless of revenue: taxi and ride-sharing operators, non-residents supplying digital services to Canadians, and platform-based short-term accommodation operators. Once registered, businesses collect GST (5 percent) or HST (rates ranging from 13 percent in Ontario to 15 percent in the Atlantic provinces) on taxable supplies and remit the net amount to the CRA after deducting ITCs. Filing frequency is monthly for annual taxable supplies above CAD 6 million, quarterly for CAD 1.5 million to CAD 6 million, and annual for supplies below CAD 1.5 million (Canada Revenue Agency, General Information for GST/HST Registrants, RC4022, canada.ca).

How do sole proprietors report business income?

A self-employed individual or sole proprietor reports business income and expenses on Form T2125, Statement of Business or Professional Activities, filed as part of the T1 Individual Income Tax and Benefit Return. The T2125 captures gross revenue, cost of goods sold, and allowable business expenses, and the resulting net income (or loss) flows to line 13500 of the T1 return, where it is taxed at the individual's combined federal-provincial marginal rates (Canada Revenue Agency, Completing Form T2125, canada.ca; CRA Guide T4002, Self-employed Business Income, 2025). A separate T2125 is required for each distinct business activity. Sole proprietors pay federal income tax at graduated rates (15 percent on income up to CAD 57,375 rising to 33 percent above CAD 253,414 for 2025), plus provincial rates. Critically, self-employment income is fully subject to Canada Pension Plan (CPP) contributions: sole proprietors pay both the employee and employer shares (a combined 11.9 percent base rate for 2025 on net self-employment income between CAD 3,500 and CAD 71,300), remitted via the T1 return. There is no Employment Insurance (EI) obligation for self-employment income unless the individual has opted into the EI self-employment program.

What are the payroll source-deduction obligations for employers?

An employer that hires employees must register for a payroll deductions account (RP account) with the CRA and withhold three mandatory deductions from employee pay: CPP contributions, EI premiums, and federal plus provincial income tax. The employer matches CPP contributions dollar-for-dollar and pays 1.4 times the employee's EI premium as the employer's EI share. For 2025, the CPP base employee rate is 5.95 percent on pensionable earnings between CAD 3,500 (the Year's Basic Exemption) and CAD 71,300 (the Year's Maximum Pensionable Earnings), plus a second-tier CPP2 rate of 4.0 percent on earnings between CAD 71,300 and CAD 81,200. The EI employee rate for 2025 is 1.66 percent on insurable earnings up to CAD 65,700, or 1.32 percent in Quebec under the provincial parental insurance plan (Canada Revenue Agency, CPP contribution rates, maximums and exemptions, canada.ca; CRA Employers' Guide T4001, Payroll Deductions and Remittances, 2025). Deductions must be remitted to the CRA by the remittance due date, which varies by average monthly withholding amount: new small employers with monthly withholding below CAD 1,000 may qualify for quarterly remittances; larger employers face accelerated remittance schedules. T4 slips reporting employment income must be issued to employees and filed with the CRA by the last day of February following the tax year.

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