--- title: "Corporate Tax Instalment Calculator: Does Your Company Owe?" url: https://www.everstonecpa.com/tax-instalment-calculator description: "Does your corporation have to pay tax instalments? Enter last year’s tax owing to see whether instalments apply and which schedule — monthly or quarterly." type: tool updated: 2026-10-05 summary: "Instalments catch profitable second-year corporations by surprise. Enter your tax owing to see whether they apply to you." faq_count: 7 publisher: EverStone CPA Inc., a Chartered Professional Accountant firm registered with CPA British Columbia and CPA Alberta service_area: British Columbia, Alberta, Ontario and Manitoba language: en-CA contact: info@everstonecpa.com · https://www.everstonecpa.com/book-online --- [Home](https://www.everstonecpa.com/) Corporate tax instalment calculator [Home](https://www.everstonecpa.com/) [Free tools](https://www.everstonecpa.com/tools) Corporate instalments Corporate instalments # Corporate tax instalment *calculator* Updated 5 October 2026 **Quick answer:** [Instalments](https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/corporations/corporation-payments/paying-instalments.html) catch profitable second-year corporations by surprise. Enter your tax owing to see whether they apply to you. **Owe instalments and not sure how much?** We work out the instalment schedule with the T2 and remind you before each payment, at a fee quoted in writing. [Get My Fixed Quote](https://www.everstonecpa.com/book-online?service=corporate-tax#enquiry-form) The first instalment year is the one that catches people, because the prior year’s tax was nil. [Ask whether yours apply](https://www.everstonecpa.com/quick-question). Net federal tax owing (highest of this year and the two prior years) Is this the corporation’s first tax year? Eligible small [CCPC](https://www.everstonecpa.com/glossary#ccpc) with a clean compliance history? Opens your own email app with the numbers filled in — add your question and a CPA replies, usually the same business day. General estimates, not tax advice. Rules change and your result depends on details a calculator cannot see; we confirm the numbers once we review your enquiry. **Nothing you type here leaves your browser.** This calculator runs entirely on your device — no figures are sent to us or to anyone else. What this calculator answers **Does my corporation have to pay tax instalments, and roughly how much per period?** Corporations past their first profitable year — the year the requirement usually appears without warning. It uses the prior-year method. The CRA allows three methods and you may use whichever is lowest, provided your estimate holds up. ## A worked example The calculator above uses these figures. It is not a CRA calculator, so treat the result as an estimate to confirm against your own figures. Worked example The values the page loads with: $12,000 of net federal tax, eligible for quarterly | Step | Figure | | Net federal tax | $12,000 | | Threshold | Instalments generally required above $3,000 | | Frequency | Quarterly, for an eligible small CCPC | | Each instalment | $12,000 ÷ 4 = $3,000 per quarter | | If not eligible for quarterly | Twelve monthly instalments of $1,000 instead | ## What it assumes, and where it stops Every estimate rests on assumptions. These are the ones that would change your number most. Assumptions and limits Where this estimate stops being reliable | Assumption | What it means for your number | | The prior-year method | Last year’s tax spread evenly. The current-year and two-year blended methods can be lower — but under-estimating creates instalment interest. | | The threshold looks back two years | Instalments are required if net tax exceeded $3,000 this year OR in either of the two preceding years. One strong year can trigger them for the next. | | First-year corporations are exempt | Which is exactly why year two surprises people: the first instalments can fall due in the same months you are paying year one’s balance. | | Instalment interest is not deductible | Unlike most interest a business pays, this is a pure cost. | General information, not advice. [Have a CPA confirm it for your situation](https://www.everstonecpa.com/book-online?service=corporate-tax#enquiry-form) The same tax, paid earlier — and briefly, twice over. ## The year-two surprise A corporation pays no instalments in its **first tax year**. After a profitable year one, the CRA expects instalments through year two while you pay year one’s balance. Unbudgeted, that overlap feels like a tax increase; it is the same tax, paid earlier. ## Three ways to calculate — pick the lowest The CRA permits the **prior-year method** (last year’s tax, spread evenly), the **current-year method** (your estimate) and a **two-year blended method**. Use the smallest, but underestimate and non-deductible interest applies to the shortfall. Current-year suits a shrinking business. The corporation tax calculator above applies the prior-year method, so it shows the safe default rather than the lowest possible instalment. ## If you have already missed some Instalment interest is charged, but it can be offset by paying later instalments early — the CRA applies a contra-interest calculation. Catching up promptly genuinely reduces the cost. [The full instalment guide](https://www.everstonecpa.com/blog/corporate-tax-installments-canada) or see the [check when your corporate return is due](https://www.everstonecpa.com/t2-deadline-calculator) for your filing and balance dates. Embed this calculator Free to use on your own site — the snippet keeps a credit link back to this page.

Calculator by EverStone CPA

Common questions ## Corporate Tax Instalment Calculator FAQ **When does a corporation have to pay tax instalments?** Generally when net federal tax owing exceeds $3,000 in the current year or in either of the two preceding years. A corporation in its first tax year is exempt. [Ask about your case →](https://www.everstonecpa.com/quick-question) **Monthly or quarterly?** Most corporations pay monthly. Quarterly instalments are available to an eligible small CCPC claiming the [small business deduction](https://www.everstonecpa.com/glossary#sbd) with a clean compliance history — meaning no recent late filings or late remittances. **What if I pay too little?** The CRA charges instalment interest on the shortfall at the prescribed rate, compounded daily and not deductible. Paying later instalments early can offset some of that interest. **Do provincial instalments work the same way?** British Columbia’s corporate tax is administered by the CRA and collected together with federal tax, so a single instalment covers both. Quebec and Alberta administer their own corporate tax and have separate instalment requirements. **How should I read the instalment amount this calculator gives me?** Treat it as a per-payment target, not a final bill. Instalments prepay the tax for the year; they stop interest accruing but do not settle the balance. If the year is stronger than planned, expect a balance due at year-end on top. **What does the instalment calculator not account for?** It ignores mid-year income changes, associated-company rules that split the small business deduction, credits, loss carrybacks and GST/HST instalments. It cannot see a different instalment base CRA may have assessed, so check your CRA account first. **When should I have my instalment plan reviewed?** Review it when revenue shifts materially, when you add a second company, or when a CRA reminder does not match your figure. After a strong or slow year, a plan based on last year can be well off; a short review before the next due date resets it. If cash cannot cover these instalments, [a CRA payment arrangement](https://www.everstonecpa.com/blog/cra-payment-arrangements-cant-pay-tax-canada) usually beats missing them; the guide explains arrears interest and negotiation. If the year-end is the problem, a [year-end email course](https://www.everstonecpa.com/year-end-playbook) paces the close. ## Related reading [The instalment reminder letter, decoded](https://www.everstonecpa.com/cra-letter-instalment-reminder) ## Want these numbers confirmed for your business? Send an enquiry to a Fraser Valley CPA. We will check the figures against your actual situation and quote a fixed fee. [Get My Fixed Quote](https://www.everstonecpa.com/book-online?service=corporate-tax#enquiry-form)[Book a Paid Advice Call](https://www.everstonecpa.com/advice-call) ## Have a question about this? Ask free through [the quick-question form](https://www.everstonecpa.com/quick-question); a CPA replies by email within one business day. For a proper look, a 45-minute **Advice Call** with a CPA is $225 plus GST, booked by email with a secure payment link and credited to your first invoice if you become a client within 60 days. Want us to take it on? [Send an enquiry](https://www.everstonecpa.com/book-online?service=corporate-tax#enquiry-form). [Ask a Free Question](https://www.everstonecpa.com/quick-question) [Book a Paid Advice Call](https://www.everstonecpa.com/advice-call) Email info@everstonecpa.com ★★★★★ “Personal. Professional. Responsive. Plus he saved me a bundle!” Corrin Skalbeck · Google Local Guide Instalments sit alongside your filing and balance-due dates. See [how the corporate deadlines fit together](https://www.everstonecpa.com/t2-deadline). --- Source: https://www.everstonecpa.com/tax-instalment-calculator Prices: https://www.everstonecpa.com/pricing · Contact: info@everstonecpa.com · https://www.everstonecpa.com/book-online