Hired an employee? Check CRA Deadlines for Employers
If you hire an employee, you have to have your employee complete a TD1 form within seven days of being hired. You also have to send your employee a T4 information slip by the last day of February following the year to which the information slips apply.
Finally, if you go out of business, the CRA requires you to submit your final CPP contributions, EI premiums, and income tax deductions (payroll remittances or source deductions) within seven days of closing your doors. It also requires you to submit any T4 slips as well as a T4 Summary and file it within 90 days.