Line 13900 on the T1 income tax and benefit return is where a self-employed person reports net commission income for the year. The figure you enter is your gross commissions minus the business expenses you’re allowed to deduct, calculated on Form T2125. Before the 2019 tax year the same line was numbered 139, so older guides and worksheets may refer to it that way.
Who Uses Line 13900
Line 13900 is for commissions you earn as a sole proprietor or through a partnership: independent sales agents, real estate agents, insurance agents, and similar contractors who are paid on commission rather than salary.1Canada Revenue Agency. Sole Proprietorships and Partnerships It sits alongside the other self-employment lines on the T1: Line 13500 for business income, Line 13700 for professional income, Line 14100 for farming, and Line 14300 for fishing.
If you’re an employee who earns commissions and receives a T4 slip, this is not your line. Employed commission salespeople report through their T4 and claim allowable employment expenses using Form T2200 signed by the employer.2Canada Revenue Agency. Employment Expenses Line 13900 is strictly for self-employed commission income.
Slips and Records Behind the Number
Businesses that pay commissions to an independent agent report those payments on a T4A slip, in Box 20 (Self-employed commissions). The amount in Box 20 does not include GST/HST or provincial sales tax you may have collected on top of your fee.3Canada Revenue Agency. T4A Slip – Information for Payers Working with multiple companies means multiple slips, and the Box 20 totals combined are your gross commission income for the year.
Not every payer issues a T4A, especially for smaller amounts or when you invoice directly. That does not change your obligation. All commission income is reportable whether or not a slip arrives, so keep your own invoices, contracts, and payment records. CRA matches T4A filings from payers against returns, and you can preview the slips filed under your name through the My Account portal before you file.4Canada Revenue Agency. Get a Copy of Your Slips
Getting from Gross Commissions to the Line 13900 Figure
Gross commissions are only the starting point. Form T2125 (Statement of Business or Professional Activities) walks you through subtracting allowable business expenses to arrive at net commission income, and that net figure is what you enter on Line 13900.5Canada Revenue Agency. Completing Form T2125 If you have commission income from more than one activity, complete a separate T2125 for each.
A positive net figure increases your total income and tax owing. A net loss can offset other income on your return, subject to the home office limitation described below.
Common Deductible Expenses
Expenses must be reasonable and incurred to earn the commission income.6Canada Revenue Agency. Self-Employed Business, Professional, Commission, Farming, and Fishing Income – Expenses Typical categories for commission earners include:
- Advertising, including online ads, print ads in Canadian publications, and finder’s fees.
- Meals and entertainment, deductible at 50% of what you spent when tied to earning income.
- Office supplies, postage, cellphone, and internet used for business.
- Commercial insurance premiums on business equipment or liability coverage.
- Bad debts you previously included in income and have determined are uncollectable.
Vehicle Expenses
Driving to meet clients or otherwise travelling for the work lets you deduct the business-use portion of vehicle costs: fuel, insurance, maintenance, licence and registration, interest on a car loan, and lease payments.7Canada Revenue Agency. Motor Vehicle Expenses The split between personal and business use comes from a kilometre log. CRA considers a full-year logbook the best evidence, recording date, destination, purpose, and distance for each business trip, plus odometer readings at the start and end of the year.
Home Office Expenses
You can deduct a share of household costs if you use part of your home for business, provided the space is your principal place of business or you use it exclusively and regularly to meet clients.8Canada Revenue Agency. Business-Use-of-Home Expenses Eligible costs include a proportional share of heating, electricity, home insurance, cleaning supplies, property taxes, mortgage interest, and rent. The proportion is usually the workspace area divided by the home’s total area, reduced further if the space is only used part-time for business.
One restriction matters for how Line 13900 comes out: home office expenses cannot create or increase a business loss. If the deduction exceeds your net commission income before home office costs, the excess carries forward to future years rather than producing a loss this year.
CPP Contributions on What You Report
Self-employed people pay both the employer and employee portions of Canada Pension Plan contributions on their net self-employment earnings, and the number on Line 13900 feeds that calculation. For 2026, the combined self-employed CPP rate is 11.9% on net earnings between the $3,500 basic exemption and $74,600 in maximum pensionable earnings, with a maximum annual contribution of $8,460.90.9Canada Revenue Agency. CPP Contribution Rates, Maximums and Exemptions
Above $74,600, CPP2 kicks in. For 2026, earnings from $74,600 up to $85,000 face a second additional contribution at a combined self-employed rate of 8%, to a maximum of $832.10Canada Revenue Agency. Second Additional CPP (CPP2) Contribution Rates and Maximums CPP and CPP2 are calculated on Schedule 8. Half of the self-employed CPP contribution is deductible on your return.
GST/HST: A Separate Obligation
Once your worldwide gross revenue from taxable supplies passes $30,000 over four consecutive calendar quarters, or in a single quarter, you must register for GST/HST, charge it on your services, and remit it.11Canada Revenue Agency. When to Register for and Start Charging the GST/HST Your commission income counts toward the threshold. Below $30,000 you are a small supplier and registration is optional, though voluntary registration lets you claim input tax credits on business purchases.
GST/HST you collect is not part of the number on Line 13900. It runs through a separate GST/HST return. Tracking a rolling four-quarter total matters, because the registration obligation can arrive quietly as income grows.
Deadlines, Instalments, and Penalties
Self-employed filers get an extended filing deadline of June 15. For the 2025 tax year, that is June 15, 2026. Any balance owing is still due by April 30, 2026, and interest accrues from May 1 regardless of the later filing date.12Canada Revenue Agency. Due Dates and Payment Dates – Personal Income Tax
If your net tax owing exceeds $3,000 in the current year and also exceeded $3,000 in either of the two preceding years, CRA requires quarterly instalment payments on March 15, June 15, September 15, and December 15. Quebec residents face a $1,800 threshold.13Canada Revenue Agency. Who Has to Pay – Required Tax Instalments for Individuals Interest on missed instalments compounds daily.
Filing late when you owe brings a penalty of 5% of the unpaid balance plus 1% for each full month the return is outstanding, up to 12 months. If CRA penalized you for late filing in any of the three preceding years and issued a formal demand to file, the repeat penalty is 10% of the balance owing plus 2% per month for up to 20 months.14Canada Revenue Agency. Interest and Penalties on Late Taxes – Personal Income Tax
Under subsection 163(1) of the Income Tax Act, failing to report $500 or more of income when you also failed to report $500 or more in any of the three preceding tax years exposes you to a repeated failure to report income penalty.15Department of Justice Canada. Income Tax Act – Section 163 Commission income is taxable and reportable whether or not you receive a T4A, and CRA’s slip-matching program makes unreported commissions relatively easy to spot.