CRA Tax Instalment Payment Calculator

CRA gives individuals three ways to work out quarterly instalments and all three are equally valid. What differs is how much you hand over during the year, and how much risk you carry if the year turns out differently. The calculator runs all three on the same figures so the trade-off is visible.

The starting question is whether instalments apply at all. CRA requires them when your net tax owing — total tax for the year less tax already withheld at source and refundable credits — is more than CA$3,000 in the current year and more than CA$3,000in either of the two preceding years. The test is strictly “more than”: net tax owing of exactly CA$3,000 does not trigger instalments. Quebec residents use CA$1,800, since CRA collects only the federal half of their tax.

Then the three methods:

1. No-calculation option.The amounts CRA prints in box 2 of the February and August instalment reminders. March and June are each a quarter of your net tax owing from two years ago; September and December split whatever is left of last year’s net tax owing after those first two payments. Pay these in full and on time and instalment interest cannot arise.
2. Prior-year option.A quarter of last year’s net tax owing on each of the four dates. This beats the reminder amounts whenever last year and the year before it were far apart — the reminder is still reaching back two years for its first half.
3. Current-year option. A quarter of what you expect to owe for the year now running. The only method that lets you pay less straight away when income drops, and the only one that can go wrong: if the year lands above the estimate, interest runs on the difference.

Picking the “wrong” method is not itself penalised: under s. 161(4.01) of the Income Tax Act, CRA works out instalment interest under all three and charges the least. The second tab reports which basis your figures were measured against.

Interest, when it applies, runs on each shortfall from its due date to your balance-due date of 30 April the following year, compounded daily at the prescribed rate for overdue taxes — 7% as at 2026-Q3, re-announced every quarter. Anything paid early or above the required amount earns credit interest at the same rate, which offsets charges on the other quarters; a net credit is never refunded. Net interest of CA$25 or less is not charged at all. Above CA$1,000 of interest, s. 163.1 adds an instalment penalty: half of the amount by which the interest exceeds the greater of CA$1,000 and a quarter of the interest you would have paid had you sent nothing at all.

Two simplifications: each payment is assumed to land on its due date, so a late payment costs more than shown; and for quarters CRA has not announced a rate for yet, the last announced rate is carried forward and the result is flagged as an estimate.

Four dates a year for individuals, unchanged from year to year. A payment CRA receives on the next business day counts as on time when the 15th falls on a weekend or public holiday.

Farmers and fishers pay a single instalment on 31 December instead, of two-thirds of the estimated tax for the year. Source: CRA — Payment due dates. Verified 2026-08-13.

• CRA — Who has to pay income tax by instalments
• CRA — How much you have to pay (the three calculation options)
• CRA — Instalment payment due dates
• CRA — Instalment interest and penalty charges
• CRA — Prescribed interest rates (announced quarterly)
• Income Tax Act s. 161 — instalment interest, including s. 161(4.01)
• Income Tax Act s. 163.1 — the instalment penalty

The rules and the prescribed-rate table were last cross-checked against these sources on 2026-08-13, with 2026-Q3 the last quarter CRA had announced at 7%. Because the prescribed rate is re-announced every quarter, this page is on a quarterly review rather than an annual one. This is general information about how the instalment rules work, not tax advice for your situation.