Self-employment income is reported on your personal tax return (T1) using Form T2125. You report your gross revenue, deduct eligible business expenses, and pay tax on the net income at your regular marginal rate. Self-employed individuals pay both the employee and employer portions of CPP - that's 11.9% of net self-employment earnings for 2026 (up to the maximum pensionable earnings). Common deductions include home office expenses, vehicle expenses (business-use percentage), office supplies and equipment, professional development and courses, advertising and marketing, and phone and internet (business portion). If your business revenue exceeds $30,000 over four consecutive calendar quarters, you must register for GST/HST. Self-employed individuals have until June 15 to file their return, but any balance owing is still due April 30.