Employees normally have income tax withheld on each paycheque by their employers, who remit the tax withheld together with payroll taxes to the CRA. Contractors (and most pensioners) are normally required to pay instalments for income tax to CRA during the year. Once a tax return is filed, a tax refund will be available if the tax withheld or the instalments are more than tax owing calculated on the tax return. If the tax return results in a balance due, it must be paid in full by the due date or interest will accrue daily.