Self-employed tax deductions in Ontario: a 2026 guide
Short answer: Ontario sole proprietors generally report business income and expenses on the federal T2125. You can usually deduct reasonable current expenses incurred to earn business income, but only the business portion—not personal costs—and you need records to support the claim.
Ontario does not create a separate list of ordinary T2125 deductions. The practical work is identifying a genuine business cost, separating business and personal use, and retaining the receipt or other supporting record.
This is general information, not tax advice. Keep records, use the current CRA forms and guidance, and ask a qualified tax professional about your circumstances.
The rule behind every deduction
The CRA's starting point is simple: a reasonable current expense incurred to earn business income may be deductible. Personal expenses are not. Some purchases are capital property rather than a current expense and are handled differently, often through capital cost allowance (CCA).
| Ask this question | Why it matters |
|---|---|
| Was this incurred to earn business income? | It tests the business connection. |
| Is the amount reasonable? | The CRA's general rule requires it. |
| Was there personal use too? | Claim only the business share. |
| Is it a current expense or capital property? | The tax treatment can differ. |
| Can you support it? | Receipts and records matter in a review. |
Source: CRA — Business expenses.
Common categories to track
These are categories worth reviewing—not an automatic checklist of deductions.
| Category | Examples | Record to keep |
|---|---|---|
| Advertising | Website, ads, design work, eligible promotion | Invoice, campaign record, payment proof |
| Professional fees | Accounting, legal, consulting | Invoice showing the service |
| Office expenses and supplies | Stationery, small consumables, business supplies | Receipt and business purpose |
| Phone and internet | The business share of a mixed-use plan | Bills plus your allocation method |
| Travel and vehicle costs | Eligible business travel and business-use vehicle costs | Receipts, itinerary or logbook, purpose |
| Rent and utilities | Business premises or qualifying home workspace share | Bills, lease, allocation calculation |
| Insurance, licences, dues | Costs tied to operating the business | Policy, renewal, membership invoice |
The precise line on Form T2125 depends on the expense and your facts. Avoid forcing a purchase into a category just because it sounds business-like.
Home office: when Ontario self-employed people may claim it
You may be able to claim business-use-of-home expenses if your workspace is your principal place of business, or you use it only to earn business income and regularly and continuously meet clients, customers, or patients there.
The CRA describes a reasonable allocation method such as workspace area divided by total home area. If a room is used personally as well, reduce the claim for the portion of time it is used personally. Qualifying costs can include a share of utilities, insurance, maintenance, rent, property taxes and mortgage interest, subject to the rules. CCA on a home deserves particular care because it can affect a later sale.
Source: CRA — Business-use-of-home expenses.
Vehicle expenses: calculate the business share
For a car used for both work and personal life, keep a trip log and the total annual kilometres. The business percentage is:
business kilometres ÷ total kilometres = business-use percentageApply that percentage to eligible actual costs, subject to the CRA rules. The CRA says a full logbook should include the date, destination, purpose, and kilometres for each business trip, plus odometer readings at the start and end of the fiscal period.
Read our detailed guide: CRA mileage rate 2026: what you can claim and how to log it.
Meals: the 50% rule catches people out
For ordinary business meals and entertainment, the CRA generally limits the deduction to 50% of the lesser of the amount incurred and a reasonable amount, with exceptions. Save the receipt and note who you met and why. Do not treat every coffee or lunch during a workday as a business meal.
Source: CRA — Meals and entertainment.
Ontario HST: do not double-count input tax credits
If you are GST/HST-registered and claim an input tax credit for the tax paid on an expense, CRA says to reduce the business expense by the input tax credit amount. Keep your tax treatment consistent between your books and return.
A monthly workflow that makes tax season easier
- Scan or save receipts as the expense happens.
- Categorize each cost while you remember its business purpose.
- Review mixed-use expenses monthly and apply a consistent method.
- Keep mileage records continuously, not from memory at year-end.
- Export your records and review them against Form T2125 before filing.
SMRTscan keeps receipt images, categories, mileage records, and exportable reports together for Canadian small businesses. It helps organize the evidence; the final tax treatment remains yours to review.
FAQ
Do Ontario sole proprietors use a different expense form?
Most sole proprietors report business or professional income and expenses on the federal T2125 as part of their personal tax return. Ontario income tax is calculated through the return; use current CRA filing instructions for your situation.
Can I deduct my cell phone and internet?
Potentially, but only the business portion. Keep the bill and document a reasonable allocation method for mixed personal and business use.
Can I claim expenses before my business officially started?
The start date and treatment of start-up expenditures can be nuanced. The CRA says you need to have carried on the business in the fiscal period for an expense to be deductible; seek advice for pre-launch costs or larger purchases.
This article is general information for Canadian small businesses and self-employed people, not tax, legal, or accounting advice. Verify current rules with the CRA or a qualified professional before filing.