Canada Pension Plan Regulations

6 (1) If an employee has made a base contribution and a first additional contribution for the year under a provincial pension plan in respect of salary and wages paid to the employee by an employer, the amount of the employee’s base contribution and the employee’s first additional contribution determined under section 5, in respect of a payment of remuneration to the employee in that year by that employer, shall not exceed the amount remaining after subtracting from the sum of the year’s maximum base contribution and the year’s maximum first additional contribution the aggregate of that employee’s base contributions and first additional 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 the calculation under subsection (1), the amount of contributions previously required to be deducted by the employer under a provincial pension plan is equal to the amount determined by multiplying the amount of those contributions by the ratio that the sum of the contribution rate for employees and the first additional contribution rate for employees under the Act bears to the sum of the corresponding rates of the provincial pension plan.

(3) If an employee has made a second additional contribution for the year under a provincial pension plan in respect of salary and wages paid to the employee by an employer, the amount of the employee’s second additional contribution determined under section 5.1, in respect of a payment of remuneration to the employee in that year by that employer, shall not exceed the amount remaining after subtracting from the year’s maximum second additional contribution the aggregate of that employee’s second additional contributions previously required to be deducted in that year by that employer under this Part or under a provincial pension plan.

(4) For the purposes of the calculation under subsection (3), the amount of contributions previously required to be deducted by the employer under a provincial pension plan is equal to the amount determined by multiplying the amount of those contributions by the ratio that the second additional contribution rate for employees under the Act bears to the corresponding rate under the provincial pension plan.