WSIB Premiums

WSIB premiums are what Ontario employers registered with the Workplace Safety and Insurance Board pay to fund the province's no-fault workplace insurance under the Workplace Safety and Insurance Act, 1997 (WSIA). WSIB uses them to pay injured workers' wage-loss benefits, health care and return-to-work costs; it receives no tax funding. The premium is a rate per $100 of each worker's insurable earnings, and the rate depends on the business activity WSIB classifies you in. For a small corporation the cost question comes with two others: whether you have to register at all, and whether the owner is covered.

Do you have to register, and by when?

Most Ontario businesses with employees, including family members and subcontractors, must register within 10 calendar days of the day the first worker starts (WSIA s. 75), and finish the registration by the last day of the following month. Registering takes about 10 minutes online and is free; in most cases the account number is issued immediately.

• The obligation turns on the business activity. Industries with compulsory coverage are listed in Schedule 1 (collective liability) of O. Reg. 175/98; Schedule 2 covers publicly funded organizations and privately owned businesses in federally regulated industries such as telephone, airline, shipping and railway, which pay the full cost of their own claims plus an administration fee instead of pooled premiums. Construction, restaurants and bars, sales and services, agriculture, manufacturing, trucking and transportation, and households hiring a domestic employee must register. Some activities are not compulsory but can opt in, such as banks, trust and insurance companies, private day cares, travel agencies, photography businesses and many hair salons. WSIB's online registration questions confirm the obligation for your activity.
• You can register before hiring, but you do not have to. Coverage then starts when the first employee starts work.
• Tell WSIB within 10 calendar days of a material change, for example if you end up not hiring or your business activity changes.
• Incorporation does not avoid WSIB. A corporation with employees has the same obligation as an unincorporated employer.

For example, an Ottawa corporation incorporated in January 2026 runs an online retail store, and its owner is the sole director and officer. It hires its first employee, a part-time shipping assistant, who starts on Monday, March 2, 2026. The corporation must give WSIB its business information by March 12, 2026 (10 calendar days) and complete the registration by April 30, 2026. The employee is covered from the first day. The owner is not, unless the corporation adds optional insurance for them.

Is the owner covered?

Outside construction, owners are not automatically covered, whether they are sole proprietors, partners or executive officers of a corporation. An executive officer's earnings are left out of insurable earnings, so a one-person corporation outside construction with no employees has nothing to insure unless the owner chooses to. An owner can apply for optional insurance for themselves, as long as any employees are covered too. Coverage lasts at least three months and continues until cancelled. WSIB suggests requesting an amount that reflects your annual salary, up to the annual maximum; an executive officer of a new corporation is insured at the amount requested. Without optional insurance, an owner injured at work cannot claim WSIB benefits.

Independent operators outside construction do not need to register.

How is the premium calculated?

Insurable earnings are each worker's gross earnings for the period, including taxable benefits in T4 box 14, vacation pay, bonuses, commissions, overtime, sick pay, room and board, and the labour portion of payments to a contractor WSIB does not treat as an independent operator. Deduct non-insurable amounts: top-ups to EI maternity benefits, severance pay when a Record of Employment has been issued, a retiring allowance paid over a series of months after employment has ended, executive officers' earnings that are not covered, and everything above the annual maximum.

The annual maximum is tied to average earnings in Ontario as measured by Statistics Canada. Once a worker's earnings reach it, the rest is not reported and attracts no premium.

The rate depends on your class. Under the Rate Framework, in place since 2020, each business is classified by its business activity using the North American Industry Classification System (NAICS). The 2026 class rate table lists 35 classes and subclasses, from A (Agriculture) to P (Other services). Class rates for 2026 run from $0.18 per $100 for Class L (Professional, Scientific and Technical) and $0.31 for E6 (Computer and Electronic Manufacturing) to $3.49 for D2 (Public Administration) and $3.55 for G3 (Foundation, Structure and Building Exterior Construction).

Your own rate moves from the class rate with your claims. A new business is assigned the class rate. After that, WSIB compares your insurable earnings, claim count and claim costs over a six-year review period with your class. The difference places you in a risk band, each about 5% apart in premium rate, and you move at most three risk bands a year (roughly 15%) toward your projected rate. The three most recent years carry the most weight, so fewer and shorter claims, helped by safety work and an early return to work after an injury, lower your rate over time. Rates for the coming year are posted in online services in November.

Worked example: a Toronto software corporation in 2026

A Toronto software development corporation registered with WSIB is classified in Class L (Professional, Scientific and Technical) and, as a new business, pays the 2026 class rate of $0.18 per $100. It pays three developers $130,000, $95,000 and $80,000 in 2026. The owner is its sole executive officer and draws a $100,000 salary.

Developer 1: $130,000, capped at            $121,700
Developer 2:                                 $95,000
Developer 3:                                 $80,000
Owner (executive officer, no optional
insurance): not insurable                         $0
Total insurable earnings                    $296,700

Annual premium: $296,700 x 0.18 / 100        $534.06

With optional insurance for the owner at $100,000:
Total insurable earnings                    $396,700
Annual premium: $396,700 x 0.18 / 100        $714.06

Insurable earnings between $20,000 and $999,999.99 put the corporation on quarterly reporting, so it reports and pays by April 30, July 31, October 31 and January 31. The same calculation for 2025 earnings uses the 2025 maximum of $117,000 and the corporation's 2025 rate.

When do you report and pay?

Reporting payroll and paying the premium are two steps. You must report even when your payroll is zero (enter 0 for each NAICS code with no earnings) or you have a credit on the account. Late reports bring a non-compliance charge, and late payments a fee.

If actual insurable earnings rise above the estimate WSIB has on file, contact WSIB within 10 calendar days to update it. Annual reconciliation applies only to monthly reporters and to accounts closed during the year: it compares premiums reported with actual premiums and is due March 31. Quarterly and annual reporters normally do not reconcile, unless a closing-account or other applicable requirement calls for it. See WSIB's reconciliation instructions.

You can report and pay through WSIB online services, business online banking (with the WSIB premium remittance and reconciliation payment types), or CRA My Business Account, which offers pre-authorized debit only.

What if you registered late, or never did?

Not registering can bring penalties, an investigation, provincial offences charges and retroactive premiums. Failing to register within 10 days is itself an offence under the WSIA. An employer registering for the first time that comes forward on its own before WSIB identifies it (through an audit, CRA data sharing, a claim or otherwise) can use voluntary registration: it pays retroactive premiums from the later of its first hire or 12 months before the month it disclosed, interest free, and penalties are waived.

It is also an offence to deduct WSIB premiums from workers' pay, or to require or permit workers to contribute toward the employer's WSIB costs (WSIA s. 95.1), and on conviction the court orders the amount repaid for the worker (s. 155). Premiums are an employer cost.

Common mistakes

• Paying premiums on earnings above the maximum. Only the first $121,700 per worker is insurable in 2026 ($117,000 in 2025).
• Assuming the owner is covered. Outside construction an executive officer is not covered until optional insurance is in place, and the officer's earnings do not belong in insurable earnings until then.
• Forgetting construction's compulsory coverage. The sole director of a small renovation corporation generally must be covered unless an exemption applies.
• Using the wrong classification. WSIB classifies by predominant business activity; the wrong class can mean a much higher or lower rate and a reclassification later.
• Treating contractors as non-workers without checking. WSIB applies its own tests, related to but distinct from CRA's employee and contractor tests. Misclassification exposes the payer to retroactive premiums.
• Skipping a zero report or missing the 10-day registration window. Both carry charges; the second is an offence.
• Reconciling when you do not have to, or not when you do. Only monthly reporters and closing accounts file the March 31 reconciliation.

Related concepts

WSIB is an Ontario employer cost separate from the federal source deductions remitted under the RP account and from Ontario's Employer Health Tax. Insurable earnings follow box 14 of the T4 slip, so taxable benefits are part of the base. Because an executive officer's own pay is not insurable without optional insurance, WSIB is a small factor in salary versus dividends outside construction.