To determine how much you may or may not have over contributed to cpp, determine how many months you were a participant. You become a participant the month following the month you turned 18. So you say you were 18 for 4 months...if that means you turned 18 on September then you were a participant from October on. Only your earnings from that point on would be subject to the calculation. Also, there is a basic exemption which is prorated...again based on the number of eligible months divided by 12. You would multiply that by $3500 and subtract the result from the income earned during your eligible months. That result is then multiplied by 4.95%. Compare this amount to box 16 of your T4 (s). If box 16 is greater then you will see the difference as a refundable credit on your tax return.
The answer is maybe. Depends how much you earned and how CPP was deducted.
Ideally you want CPP to accumulate.
To determine how much you may or may not have over contributed to cpp, determine how many months you were a participant. You become a participant the month following the month you turned 18. So you say you were 18 for 4 months...if that means you turned 18 on September then you were a participant from October on. Only your earnings from that point on would be subject to the calculation. Also, there is a basic exemption which is prorated...again based on the number of eligible months divided by 12. You would multiply that by $3500 and subtract the result from the income earned during your eligible months. That result is then multiplied by 4.95%. Compare this amount to box 16 of your T4 (s). If box 16 is greater then you will see the difference as a refundable credit on your tax return.