T2125 Form Canada: The Complete Guide for Sole Proprietors

Form T2125 (Statement of Business or Professional Activities) is the CRA tax form every Canadian sole proprietor and self-employed person files as part of their T1 personal tax return. It's where you report your business income, claim your deductions, and calculate your net business income. This guide explains every section in plain language.

Who needs to file a T2125?

Most Canadian sole proprietors and self-employed individuals with business or professional income file a T2125 — including freelancers, consultants, contractors, side hustlers, eBay and Etsy resellers, rideshare drivers, and tradespeople. T2125 is generally not required if your only income is employment income (T4) or investment income, though every situation differs and some activities may be reported differently depending on their nature. Note that T2125 is separate from GST/HST registration — you must report self-employment income on T2125 regardless of whether you are GST-registered.

Where does T2125 fit in your tax return?

T2125 is not a separate tax return — it lives inside your T1 personal tax return. Your net business income from T2125 flows into your total income on your T1, where it's taxed at your personal marginal rate combined with provincial rates. This is what makes sole proprietorship different from incorporation — your business profit is your personal income.

The key sections of T2125

T2125 expense lines explained

Key lines below. For a full plain-English breakdown of every line with examples, see the T2125 line-by-line guide →

The home office deduction

If your home is your principal place of business (you do more than 50% of your work there), you can deduct a portion of your home costs. Calculate your workspace as a percentage of your total home square footage. Apply that percentage to eligible expenses: heat, electricity, insurance, property taxes, and rent (or mortgage interest if you own). Your home office deduction is subject to a deduction limitation — CRA generally restricts it from creating or increasing a business loss, and unused amounts carry forward to future years.

Capital Cost Allowance — why you can't just expense equipment

When you buy a computer, camera, or other equipment for your business, you can't deduct the full cost in the year of purchase. Instead it's depreciated over time through CCA. Computers fall under Class 50 (55% per year, half-year rule in year one = 27.5%). For equipment acquired between 2025 and 2029, the Accelerated Investment Incentive can substantially increase this first-year claim (see our capital cost allowance guide). Keep your purchase receipt, date acquired, and cost — you need this every year you claim CCA.

GST/HST and T2125 — an important distinction

If you're registered for GST/HST, your T2125 income figures use pre-tax revenue — not the gross amount your clients paid including GST. The GST you collected belongs to CRA and is never your income. Line 8000 should show your revenue before GST. This is different from your GST34 return where Line 101 includes GST in the gross amount. If you qualify, the GST Quick Method Calculator can simplify how you calculate what you remit.

Key deadlines

Two important dates: your taxes owing must be paid by April 30 to avoid interest charges. Your T1 return (including T2125) can be filed as late as June 15 if you or your spouse have self-employment income — but any taxes owing still must be paid by April 30.

Common T2125 mistakes

How the numbers flow: Line 8299 to Line 9946

T2125 calculates your net business income in a straight sequence. Understanding the flow helps you see where each deduction reduces your taxable income:

Line 9946 flows directly into your T1 personal return as business income. It is then subject to personal income tax at your marginal rate and CPP contributions — which is why two people with identical T2125 net income can owe very different amounts.

Motor vehicle expenses — the rules in detail

Vehicle expenses are one of the most audited areas on T2125. CRA's rule is clear: no mileage log, no deduction. Your log must record the date, destination, business purpose, and kilometres driven for every business trip. At year end you calculate your business-use percentage:

That percentage is applied to all your actual vehicle costs — gas, insurance, repairs, car washes, parking, and loan interest — to arrive at your deductible amount. The result goes on Line 9281 of T2125.

Class 10.1 is subject to a half-year rule in year one (15% instead of 30%) and the CCA cost is capped at $39,000 before tax for vehicles acquired in 2026. Loan interest on a passenger vehicle is capped at $300/month. Keep all receipts and your mileage log for 6 years.

CPP contributions — the hidden cost of self-employment

This is the most common financial surprise for first-time T2125 filers. Employees pay half of CPP and their employer pays the other half. Self-employed individuals pay both halves — there is no employer to split the bill.

Source: CRA — CPP contribution rates, maximums and exemptions

CPP is calculated on your net self-employment income from Line 9946 — after all T2125 deductions. A higher deduction total means less CPP owing, not just less income tax. The $3,500 basic exemption means the first $3,500 of net self-employment income is exempt from CPP.

The upside: half of your CPP contribution (the employer half) is deductible on your T1 return — CRA gives it back as a credit. You will also accrue CPP retirement benefits based on your contributions.

Business activity codes (NAICS) by business type

Part 1 of T2125 asks for a 6-digit industry code. If more than 50% of your business is one specific activity, use the code for that activity. If you file on paper, you enter the code from Statistics Canada's NAICS Canada 2022 Version 1.0 list. If you file electronically, use the industry codes in your tax software (CRA Guide T4002, “Industry codes”). CRA explains this on its industry codes page.

Below are the codes NorthOS suggests for each type of business, the same list its code picker offers in onboarding and Settings. Open the type that fits you.

Source: Statistics Canada, NAICS Canada 2022 Version 1.0, checked October 1, 2026. The activity names and the grouping are NorthOS's; the official class title is Statistics Canada's. This is NorthOS's list, not every class: Statistics Canada's full list has more.

What if T2125 shows a net loss?

A net loss on T2125 is a non-capital loss. You can apply it against any other income on your T1 return — employment income, rental income, investment income — which reduces your overall tax bill. If you cannot fully absorb the loss in the current year, you can:

• Carry back up to 3 years — apply the loss to a prior year's return and get a refund of tax already paid. Use CRA Form T1A.
• Carry forward up to 20 years — reduce taxable income in a future year once the business is profitable.

Note: CRA may challenge losses if the activity does not appear to have a reasonable expectation of profit. A hobby-level activity with repeated losses over many years can be reclassified as a personal endeavour, disallowing the deductions. Keep records that support the commercial nature of your business.

T2125 filing checklist — what to gather

Use this before you sit down to file. CRA requires documentation for every line — keeping receipts and records organized throughout the year makes filing much faster.

This guide is for informational purposes only and does not constitute tax advice. CRA rules can change — always verify with the CRA T4002 guide or a qualified tax professional.