Canada Pension Plan Regulations

6 (1) Where an employee has made a contribution for the year under a provincial pension plan in respect of salary and wages paid to him by an employer, the amount of the employee’s contribution determined under section 5 in respect of a payment of remuneration to him in that year by that employer shall not exceed the amount remaining after subtracting from the year’s maximum contribution the aggregate of that employee’s contributions previously required to be deducted in that year by that employer under this Part or under a provincial pension plan.

(2) For the purposes of sections 10 and 13 of the Act, the salary and wages on which a contribution has been made for the year by an individual under a provincial pension plan is an amount equal to the aggregate of all contributions required to be made by the individual in that year under a provincial pension plan in respect of salary and wages, divided by the contribution rate for employees for the year.