WSIB for Ontario employers, explained
Most Ontario employers must register with the WSIB for workplace-injury coverage and report payroll to calculate premiums.
The Workplace Safety and Insurance Board (WSIB) provides workplace-injury coverage in Ontario. Most employers are required to register, report their payroll, and pay premiums based on their industry classification.
What you have to do
Register when you take on workers, report insurable earnings on schedule, and keep payroll records that support your premium filings. Some businesses also need clearance certificates to work with other contractors.
Why clean records matter
WSIB premium reconciliations and clearance requests are painless when payroll is accurate all year, and painful when it isn't. Current books mean your reporting lines up the first time.
What triggers registration, and how premiums are calculated
Most Ontario employers must register with the WSIB once they hire their first worker — generally within 10 days of that hire — and coverage is mandatory for the great majority of industries. Premiums are not a flat tax: they are your insurable payroll multiplied by a premium rate set for your classification, which is why two businesses with identical payroll can pay very different amounts.
| What drives your premium | How it works |
|---|---|
| Classification | Your business is assigned to a class based on what it actually does; each class carries its own premium rate |
| Insurable earnings | Reported payroll, subject to an annual maximum per worker that the WSIB sets each year |
| Reporting frequency | Monthly, quarterly, or annual, based on your premium size |
| Claims experience | Your safety record can move your rate over time relative to your class |
Premium rates and the annual maximum insurable earnings amount are set by the WSIB and change annually — confirm the current figures for your classification directly with the WSIB.
Construction, executive officers, and clearance certificates
Two situations trip up Ontario employers. First, construction has its own rules: coverage requirements extend to independent operators, sole proprietors, and partners in construction, with a narrow exemption available for one executive officer per business who does no construction work. Assuming a construction sole proprietor is outside the system is a common error.
Second, clearance certificates. Before you pay a contractor, a clearance certificate confirms their WSIB account is in good standing — and if you skip it, you can end up liable for their unpaid premiums. Contractors get asked for their own certificates constantly. Both problems disappear when payroll records are accurate all year, because reconciliations and clearance requests become lookups rather than reconstructions.
This is general information, not tax advice for your situation. Get started and a Canadian accountant will give you the answer for your business.
Common questions
Does every Ontario business need WSIB coverage?
Most employers with workers do, though there are exceptions by industry and structure. Confirm your obligation for your situation.
What is a clearance certificate?
It's WSIB confirmation that a business's premiums are up to date, often required before one contractor pays another. Clean records make it routine.
When do I have to register with the WSIB?
Generally within 10 days of hiring your first worker, since coverage is mandatory for most Ontario industries. Registration obligations also extend further in construction, where independent operators, sole proprietors, and partners are generally covered, with a narrow exemption for one non-construction executive officer.
How are WSIB premiums calculated?
Your insurable payroll multiplied by the premium rate for your business classification, subject to an annual maximum of insurable earnings per worker. Rates vary substantially by classification and can move with your claims experience. Because the rates and the maximum change annually, confirm your current figures with the WSIB rather than repeating last year’s numbers.
What is a clearance certificate, and do I need one?
It confirms a contractor’s WSIB account is in good standing at a point in time. If you hire a contractor without one, you can be held liable for their unpaid premiums — which makes requesting clearances a routine part of paying subcontractors, not a formality.