Starting or expanding a construction business in Ontario requires navigating a layered system of federal, provincial, and municipal permits and licences. Missing a single requirement can result in stop-work orders, fines, or liability exposure that can shut down a project — or an entire business. This guide walks through every essential permit and credential you need to operate legally in Ontario's construction industry.
Business Registration and Structure
Before you can pull any permits, your business must be properly registered. In Ontario, this starts with:
- Business name registration with ServiceOntario (if operating under a name other than your legal name). Sole proprietorships and partnerships must register within 60 days of starting business.
- Corporation registration through the Ontario Business Registry if you are incorporating. Many construction businesses incorporate for liability protection.
- HST registration with the Canada Revenue Agency (CRA) once your revenue exceeds $30,000 in any four consecutive calendar quarters. Most construction businesses hit this threshold quickly.
- Employer accounts — If you hire employees, you need CRA payroll accounts for income tax, CPP, and EI deductions.
WSIB Coverage
The Workplace Safety and Insurance Board (WSIB) coverage is mandatory for construction businesses in Ontario — this is not optional. Unlike many other industries where WSIB is only required if you have employees, construction is a "compulsory" industry. Even independent operators with no employees must register. Operating without WSIB coverage can result in fines of up to $25,000 for individuals and $100,000 for corporations, plus you become personally liable for any workplace injury costs.
Trade Licences and Certifications
Ontario regulates 23 skilled trades as compulsory certification trades, meaning you must hold a valid Certificate of Qualification to practise them:
- Electrician (309A Construction and Maintenance)— Regulated by the Ontario College of Trades and enforced under the Building Code Act.
- Plumber (306A) — Requires a Certificate of Qualification and a licence from the Technical Standards and Safety Authority (TSSA).
- HVAC technician (313A and 313D) — Refrigeration and air conditioning mechanics must be certified.
- Sheet metal worker (308A), steamfitter (307A), and sprinkler fitter (427A) are also compulsory.
Red Seal endorsement is highly recommended for any compulsory trade. It allows you to work interprovincially without additional certification — valuable if you take projects in other provinces.
Building Permits
Building permits are issued at the municipal level and are required for virtually any construction, renovation, or demolition work. In Ontario, the Building Code Act mandates that a building permit must be obtained before starting construction. The application typically requires:
- Completed application forms and applicable fees.
- Two sets of construction drawings prepared by a qualified designer.
- Site plan showing setbacks, lot coverage, and grading.
- Proof of compliance with zoning bylaws.
- Engineering reports where required (structural, geotechnical, environmental).
Processing times vary by municipality: Toronto averages 10 to 15 business days for a residential permit, while smaller municipalities may be faster. Commercial and industrial permits can take 20 to 30 business days or longer.
Health and Safety Requirements
Ontario's Occupational Health and Safety Act (OHSA) imposes specific obligations on construction employers:
- All construction workers must complete the free Ministry of Labour Basic Awareness Training before starting work on any construction project.
- Projects over $50,000 require a designated constructor and a written health and safety policy.
- A Joint Health and Safety Committee (JHSC) is required on projects with 20 or more workers.
- Working at heights training is mandatory for all workers who may use fall protection on construction projects.
Key Takeaways
- WSIB coverage is mandatory for all Ontario construction businesses, including independent operators with no employees.
- 23 trades in Ontario are compulsory certification — practising without credentials carries fines and legal liability.
- Building permits are municipal — check requirements with each municipality where you work.
- Health and safety training requirements are non-negotiable under OHSA, and fines for violations are substantial.
- Keep a compliance calendar for licence renewals, WSIB premium payments, and training refreshers.