How Do I Determine Annual Insurable Earnings? For each worker on your payroll: separate out their insurable gross earnings from the earnings that are not insurable. (Contact your WSIB customer service representative or account manager if you have any questions about what earnings to include or not to include in premium calculations.) apply the annual maximum amount for insurable earnings to eliminate excess earnings not covered. Annual insurable earnings are the amounts usually reported on your workers' pay or wage stubs and on T4 slips as gross earnings. These amounts include: deductions for income tax CPP and employment insurance Insurable earnings can also include earnings not reported on a T4 such as room and board, bonuses and commissions. The maximum amount to include for each worker is $77,600 for premiums in 2010. We set this maximum amount for insurable earnings each year, based on the average industrial wage (AIW) for Ontario.