If you calculate taxable benefits for your employees you should do so before you make the last payment of source deductions for 2018, which is due on January 15, 2019.
The most common taxable benefit is an employee using an employer owned vehicle. There is a standby charge calculation and an operating cost calculation that leads to additional income being reported on the employees T4. If the employee has not already maxed out on CPP, then additional CPP will need to be paid on this standby charge and it is due by January 15th. The last payment for 2018 is due on January 15, 2019 which is coming right up.
It is a great idea to do the T4’s for 2018 before January 15th so that you can see exactly how much money to send CRA on January 15th to avoid interest on outstanding amounts. fffffffff