CPP being calculated on payment that is less then the period exemption

E1 9.2 Canadian Payroll

We have seen instances where an employee is being paid an amount that is less then the CPP period exemption (Bi-weekly $3500/27 = $129.63) and CPP is being calculated as a credit.

As an example the pay is only 5 hrs for a Gross of $96.93. When the payroll is processed the CPP shows as being -1.72. The payroll staff have to reset the payroll and pull this employee into an interim and override the CPP so there is no credit being paid to the employee.

I have reviewed the Vertex documentation on how CPP is calculated and I am able to duplicate the calculation. But I have questions on why it is working as it is. We have Self Adjust turned on and when I follow that calculation process I found that the cause of the credit calculation is tied to the fact that Vertex uses the full period exemption($129.63) when in fact it, in my opinion, should only be the gross amount of $96.93. This makes the calculated YTD exemption larger, which when used in the rest of the CPP calculation for the period