Where vacation pay is calculated on a percentage basis and paid to an employee who is taking holidays, you must use the applicable section of the Source Deduction Table for Québec Income Tax (TP-1015.TI-V), as indicated below:
To calculate the amount of income tax to withhold from the vacation pay of an employee who is not taking holidays, use the method for bonuses.
Payments that you make to a trust, as credits for vacation time accumulated by an employee, must be included in the employee's income for the year in which the payments are made. The payments are subject to source deductions of income tax just as if they had been paid directly to the employee.