Tax instalments,
explained.

Examples are illustrative, in Canadian dollars, and assume full 12-month years. The $12,000 instalment plan is an example, not a calculation of your required payments. Income-tax examples are after other applicable credits and withholding, before instalments. GST/HST examples use net tax.

Dates shown are the usual dates before weekend and CRA-recognized holiday adjustments. Use your actual tax year and CRA schedule. Farming and fishing have special personal instalment rules. Short years, first-year GST/HST annualization, and unusual corporate taxes require separate calculations.

Quarterly corporate instalments are only for eligible small Canadian-controlled private corporations. Confirm the applicable compliance, income, capital and other eligibility requirements before switching. Alberta and Quebec administer their own provincial corporate income tax separately.

Personal instalment calculations may include CPP contributions and voluntary EI premiums. A first personal reminder arriving only in August may use a different September/December split. A reminder is a starting point; current-year circumstances still matter.

Required instalments are not optional. Income-tax instalment interest is calculated from the instalment due date, with payments credited under CRA’s rules. GST/HST instalment interest starts the day after the missed due date. Arrears interest starts the day after the final balance is due on tax still unpaid. Both generally use the prescribed overdue-tax rate for the period, compounded daily. Personal and corporate income tax can also attract an instalment penalty when instalment interest exceeds $1,000; the precise formula determines whether a penalty results. GST/HST late or short instalments generally attract interest without this income-tax instalment penalty. A late-filing penalty is separate and generally applies when a return is late and tax is owing. A lower current-year estimate can reduce instalments, but an underestimate may cause interest. Keep the correct tax account and year on every payment.

Final balances: personal income tax is generally due April 30 of the next year, including for self-employed people whose filing deadline is generally June 15. Corporate balances are generally due two months after year-end, or three months for qualifying CCPCs. Annual GST/HST balances are generally due three months after year-end; individual annual filers with business income and a December 31 year-end generally pay by April 30 and file by June 15.

Educational overview, checked September 11, 2026. Your accountant can confirm the amounts, accounts and deadlines that apply to you.