Enter last year’s total corporate tax to see whether instalments are required at all, whether you qualify for the quarterly schedule, and what each payment is under the prior-year option. Figures reflect the 2025 tax year rules.
Your corporation
How it works. Instalments only apply once tax owing passes $3,000. Under the prior-year option, last year’s total tax is split into twelve monthly payments — or four quarterly ones for small CCPCs with a clean compliance record — each due on the last day of its month or quarter. Provinces that collect their own corporate tax run a parallel test on the provincial amount.
Quarterly instalment
$0
Based on the prior-year option. The current-year and combined options can lower payments when income is falling.
An estimate is a starting point. Get your real number.
This calculator uses published rates. Your actual position depends on the credits, deductions and structure behind your numbers.
- A professional tax accountant reviews your figures, not a formula
- Fixed quote before any work starts
- You pay after you approve the filing
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How corporate tax instalments work
A corporation has to prepay its tax through the year once tax owing is more than $3,000 both this year and last — below that, the whole bill can simply be paid with the return. There are three ways to size the payments: the prior-year option (last year’s tax divided evenly, which is what this calculator shows), the current-year option (this year’s estimated tax), and a combined option that starts from the year before last. CRA charges no interest as long as the payments match whichever option produces the lowest total, so a corporation whose income is falling can safely pay less than the prior-year amount.
The default schedule is monthly, due the last day of each month. Small CCPCs earn the lighter quarterly schedule — four payments due the last day of each quarter — if the corporation claimed the small business deduction with taxable income of $500,000 or less, has taxable capital of $10 million or less, and has a perfect compliance record for filings and remittances. Lose the perfect record and the schedule reverts to monthly. Provinces that collect their own corporate tax apply their own thresholds and schedules alongside CRA’s.
What this calculator does not cover
It does not compute the current-year or combined options, which need an income forecast rather than a single input — worth doing when income is dropping, since they can cut the payments legitimately. It also does not handle a corporation’s first tax year (instalments are generally not required until there is a prior year of tax to measure against), short tax years, or the separate provincial instalment systems where they exist. Instalment shortfalls attract interest at CRA’s prescribed rate, and persistent large shortfalls can add a penalty on top. For the surrounding dates — year-end filing and balance-due deadlines — use the tax deadline calculator, or have our corporate tax team set the schedule for you.
| Condition | Requirement |
|---|---|
| Threshold | Tax over $3,000 this year and last |
| Quarterly option | CCPC, clean compliance, income ≤ $500k, capital ≤ $10M |
| Otherwise | Monthly |
Rates reviewed for the 2025 tax year by Udit Gupta, Founder and Tax Accountant. Federal and provincial rates change annually, and this tool is an estimate for planning rather than tax advice. Confirm current figures before relying on them for a filing.
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Rates and method reviewed by Udit Gupta
Ex Big 4 — Ernst & Young, Deloitte · International & cross-border tax specialist · CPA Canada (In-Depth Tax Program) · Chartered accountant, ICAI & MIA
Udit Gupta has over 15 years of experience helping corporations and business owners with corporate structuring, corporate tax filing, bookkeeping, payroll, GST/HST, cross-border tax and CRA representation. He is Big 4 trained, at Ernst & Young and Deloitte, and qualified as a chartered accountant in India and again in Malaysia. In 2014 he founded his accounting practice to serve entrepreneurs, startups and non-resident business owners across Canada. View full member bio.
The Institute of Chartered Accountants of India — member 521458 · Malaysian Institute of Accountants — member CA 44667 · Ex Big 4: Ernst & Young, Deloitte · CPA Canada (In-Depth Tax Program), completed 19 Dec 2023 · In-Depth GST/HST Part I, 12 Jul 2022 · Part II, 5 Jul 2023
Editorial policy. Every page is researched against primary sources — the Income Tax Act, CRA publications and CPA Canada guidance — and every rate or threshold is stated with the tax year it applies to.
Sources. CRA — Corporations · CRA — Corporation tax rates · Income Tax Act (Justice Laws Website)