SimpleTax Help

The CPP contributions on line 308 aren’t what I was expecting. Why?

Starting in the 2014 tax year, the CPP contributions on line 308 or 310 of the Schedule 1 are calculated on a Schedule 8 (or on a RC381 if you have income from Québec). You can see how the amount has been calculated by reviewing the relevant document in the Tax DocumentsDocuments section.

The most common reason that box 308 won’t match box 16 of your T4 slip(s) is because your employer did not withhold the correct amount of CPP. This is very common and happens most frequently if you have multiple employers.

If line 308 is showing $0, and you know you aren’t exempt from the CPP, you might have:

  • entered $0 in box 26 of your T4 slip (if that box is blank on your T4, leave it blank in SimpleTax), or
  • indicated that you are exempt from CPP in box 28 of your T4 slip.

If there is a number in box A of your Schedule 8 (or box A and/or B of your RC381) it means your CPP contribution have been prorated. This happens when:

  • you turned 18 or 70 in the year,
  • this is the first year you received CPP benefits, or
  • you are between the ages of 65 and 69 and you elected to stop making CPP contributions at some point during the year (or you revoked an election you made in a prior year).