If you earn income that isn't subject to payroll withholding — from self-employment, rental properties, investments, or pension income — the Canada Revenue Agency (CRA) expects you to remit tax throughout the year rather than in one lump sum at filing time. This pay-as-you-go system is called quarterly tax instalments, and missing or underpaying them triggers daily compounding interest charges. Here is a complete guide to how instalments work in 2025, who must pay them, how to calculate the right amount, and how to stay on the CRA's good side.
The threshold that triggers an instalment obligation applies to individuals whose net tax owing exceeds $3,000 in the current year and in at least one of the two preceding years. "Net tax owing" means your total federal and provincial tax after all withholding at source — so employment income with proper T4 deductions usually doesn't generate a requirement, but the following situations commonly do:
Quebec residents face a lower threshold: the trigger is $1,800 in net tax owing rather than $3,000, and instalments are split between the CRA (federal) and Revenu Québec (provincial) separately.
The two-year lookback means a one-time spike in income doesn't automatically create an instalment obligation — you need to have exceeded the threshold in the current year and in either 2023 or 2024 (for the 2025 tax year) to be required to pay. First-year business owners or those who had a large one-off gain often aren't required to pay instalments, though it can still be wise to do so voluntarily to avoid a large April balance.
For individuals, CRA requires four equal instalments spread across the calendar year. The 2025 due dates are:
Each instalment represents approximately one-quarter of your estimated annual tax liability. Missing a due date — even by a single day — starts the instalment interest clock. Note that farmers and fishers operate under different rules and are only required to make one instalment per year, due December 31.
CRA allows three different calculation methods. Choosing the right one can save you money or, if chosen poorly, cost you in interest charges.
Under this approach, you base each quarterly payment on one-quarter of your previous year's net tax owing. This is the simplest method and provides a clear safe harbour: if you pay at least 25% of last year's tax per quarter, CRA will not charge you instalment interest — regardless of what you ultimately owe when you file.
Example: You owed $20,000 in net tax for 2024. Under the prior-year method, you pay $5,000 on each of the four 2025 due dates. Even if your 2025 income rises and you end up owing $28,000, you owe no instalment interest — just the $8,000 balance plus regular arrears interest after April 30, 2026.
This method works best when income is relatively stable or growing, and you prefer predictability over precision.
Here you estimate what you expect to owe for the current year and pay one-quarter of that estimate each quarter. This method is more flexible but carries risk: if you underestimate, CRA will charge instalment interest from each due date on the shortfall.
The current-year method works well when your income has dropped significantly from the prior year — for instance, if you sold a rental property in 2024 that generated a large capital gain but won't repeat that income in 2025. Paying based on 2024's inflated tax bill would mean overpaying all year and waiting until your 2025 refund to get money back.
Each year, CRA mails or posts instalment reminder notices through My Account. The March and June reminders are based on your net tax from two years ago (2023 for the 2025 tax year). The September and December reminders are adjusted based on last year's return (2024).
If you pay exactly the amounts shown on each CRA reminder — no more, no less — you are in the safe harbour. CRA will not charge instalment interest even if you end up owing more than the reminder amounts at filing time. This method requires no math on your part and is especially helpful if your income is relatively consistent year over year.
Many clients of Swift Accounting Calgary use the no-calculation method as a stress-free baseline, then switch to the current-year estimate if their income changes materially mid-year.
If you pay less than the required instalment amount, CRA charges instalment interest at the prescribed rate plus 4 percentage points. In 2025, the prescribed rate has been running at 5–6%, making effective instalment interest approximately 9–10% annually, compounding daily from the missed due date.
Interest is calculated separately for each quarter. A shortfall in March begins accruing interest from March 15 forward — it doesn't wait until year-end.
There is one piece of good news: if you overpay in one quarter, the excess earns an instalment credit that offsets any interest owing on underpayments in other quarters. CRA nets the interest and credit together, so strategic overpayment early in the year can reduce or eliminate interest on a later shortfall. The credit calculation is complex, but CRA performs it automatically when processing your return.
These two types of interest are separate charges and are easy to confuse:
You can owe both simultaneously if you underpaid instalments and still have a balance owing after April 30.
Corporations operate under a separate instalment regime. A corporation must make monthly tax instalments if its federal tax for the current or prior year exceeds $3,000. Small Canadian-controlled private corporations (CCPCs) that meet certain conditions may qualify for quarterly instalments instead.
Unlike individuals, corporate instalments are due within three months of the corporation's fiscal year-end rather than on fixed calendar dates, and the final balance is due two or three months after year-end depending on the corporation type. The same three calculation methods (prior-year, current-year estimate, and CRA notional amounts) apply to corporations.
CRA offers several convenient payment channels for individual instalment payments:
Always keep proof of payment. If CRA misapplies your instalment, a payment confirmation is the fastest way to resolve the discrepancy.
CRA will charge instalment interest at the prescribed rate plus 4% (approximately 9–10% in 2025) from the missed due date, compounding daily. There is no separate penalty for missing an instalment — only interest — but the daily compounding means a skipped quarter can add up quickly by year-end. If you miss a payment, make it up as soon as possible to limit further accrual.
Yes. The legal obligation to pay instalments arises from the Income Tax Act, not from receiving a reminder notice. CRA reminders are a convenience, not a prerequisite. If you meet the $3,000 threshold (or $1,800 in Quebec) and don't receive a notice — perhaps because you moved or recently started self-employment — you are still required to make payments by the due dates. Consult an accountant to determine your obligation.
You can pay more than required in any quarter, and CRA will credit the excess against future instalments. However, you cannot pay all four quarters in advance as a single December payment and avoid interest on the March, June, and September shortfalls — each quarter's interest is calculated independently from its due date. To avoid interest entirely, you must meet the safe-harbour threshold by each due date.
The team at Swift Accounting Calgary reviews your prior-year returns, current-year income projections, and any major transactions (property sales, business dispositions, RRSP conversions) to recommend the instalment method that minimises your cash-flow commitment while keeping you out of interest territory. We also set up calendar reminders for each due date and flag mid-year if a change in income warrants adjusting your instalment amounts. Reach out if you'd like to get ahead of your 2025 obligations.
Understanding quarterly tax instalments is straightforward once you know which method fits your situation — but the daily compounding interest and multiple due dates leave little room for error. Whether you're self-employed, a landlord, an investor, or a retiree, getting your instalments right protects your cash flow and keeps CRA correspondence to a minimum.
Need help calculating your 2025 instalments or catching up on missed payments? Contact Swift Accounting today for a personalized instalment review.
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