Understanding premium rates

The WSIB is funded by the premiums we receive from Ontario businesses. Your premiums go toward helping people who experienced a workplace illness or injury by providing:

  • funds to replace lost wages
  • payment of health care costs
  • a support team of caring professionals who aim to get your employee back to work
  • benefits to the family or dependents of people who suffered a work-related death

How we determine premium rates

Classification units and rate groups

We group businesses that do the same business activities into Classification Units (CUs). CUs are then placed into rate groups based on similar expected risks and rates of injury and illness. Each year, we set premium rates for each rate group according to the group's injury and illness record and costs. Rate groups that have higher risks for injury and illness are charged higher premiums.

Your CU, rate group and premium rate are printed on your premium remittance form.

See the Employer Classification Manual (ECM) for descriptions of the CUs we use to classify your business activities.

Parts of a premium rate

Generally, your classification unit and rate group remain the same over time. Each year, we determine the premium rate for each rate group by looking at three factors:

  • New Claims Cost: the projected total future cost of injuries expected to arise during the upcoming year
  • Past Claims Cost: a charge to recover the WSIB’s Unfunded Liability
  • Administration expenses: the cost required to administer the workplace compensation system in Ontario and fulfill legislative obligations

Health and safety incentives

Through various programs and incentives, we reward companies with good health and safety records. While your basic premium rate is the same as other firms in your rate group, the experience rating programs defined below mean that your actual premium may be higher or lower.

We offer three experience rating programs that allow an individual employer’s experience to influence the rate it is charged, these include: 

  • Merit Adjusted Premium (MAP) program for small businesses
  • CAD-7 program for the construction industry
  • New Experimental Experience Rating (NEER) program for medium to large businesses

The size of your payroll

The actual premium you pay depends on the annual insurable earnings in your company's payroll. Each year, we adjust the maximum insurable earnings that you must pay premiums on.

See how to calculate your premiums.

We sometimes audit businesses to ensure accurate payroll reporting and proper rate group classification. Find out more about business audits.