Tax instalments in Canada — sometimes called quarterly tax payments — are required when CRA expects you to owe more than $3,000 in tax for the year (or $1,800 in Quebec) beyond what’s withheld through source deductions. Missing instalment due dates triggers interest charges even if you file on time and pay your full balance by April 30. Pathak Professional Corporation in Mississauga helps self-employed individuals, investors, and business owners manage their quarterly tax instalments to minimize interest and avoid CRA penalties. Call 437-872-7399.

Who Must Pay Tax Instalments in Canada?

CRA requires quarterly instalments when your net tax owing exceeds $3,000 in BOTH of the last two years. “Net tax owing” means: federal income tax after all credits − tax withheld at source (T4 employment income, RRSP income, pension income). Common situations where instalments are required:

• Self-employed individuals (T2125): No employer withholding source deductions; all income tax is paid through instalments or the April 30 balance
• Rental income: No withholding on rental income; net rental income taxes are paid through instalments
• Investment income: Interest, dividends, and capital gains not subject to withholding
• Business owners taking dividends: Dividends don’t have source deductions; tax is due through instalments
• Retirees with pension + investment income: If CPP, OAS, and pension income together with investment income exceed $3,000 in additional tax after T4/pension withholding
• Employees with side income: Employment income from one job plus significant side income that generates over $3,000 additional tax

2025 Tax Instalment Due Dates (Personal T1)

Three Methods to Calculate Tax Instalments

CRA provides three calculation methods — you can choose the one that minimizes your payments without triggering instalment interest:

Method 1: No-Calculation Method (CRA Tells You)

CRA sends an instalment reminder notice twice a year (February and August) with the amounts it expects you to pay. These amounts are based on your prior prior-year tax (the year before last). If you pay exactly the amounts on the CRA reminder, CRA will NOT charge instalment interest — even if your actual tax for the current year is higher. This is the safest method if you receive CRA instalment reminders.

Method 2: Prior Year Tax Method

Pay 25% of your total prior year’s net tax in each of the four instalments (March, June, September, December). If prior year total net tax = $20,000: pay $5,000 each quarter. If you actually owe more this year, you pay the difference (with no instalment interest) when you file your April 30 return. No interest if you pay exactly 25% × prior year tax for each instalment.

Method 3: Current Year Tax Method

Estimate your current year’s total tax and pay 25% of that estimate quarterly. If you estimate correctly (within a reasonable range), no instalment interest. If you underestimate, you’ll owe instalment interest on the shortfall. Most useful when your income has decreased significantly from the prior year and you don’t want to overpay instalments. Requires you to accurately forecast current-year income.

Instalment Interest — How CRA Charges It

CRA charges instalment interest at the prescribed rate plus 4% (currently 9% per annum) on any shortfall in instalments, compounded daily from each instalment due date until the balance is paid. Instalment interest is charged on the LESSER of:

• The difference between what you should have paid each quarter (using the prior year method) vs what you actually paid
• The actual tax owing at April 30 after all credits

Important: instalment interest is NOT tax-deductible for individuals (unlike business interest). Pathak Professional Corporation calculates instalment interest exposure for self-employed clients to ensure no unnecessary interest is paid. Call 437-872-7399.

Tax Instalment Penalty — Worse Than Interest

In addition to interest, CRA can charge an instalment penalty when the total instalment interest for the year exceeds $1,000. The penalty formula:

Instalment penalty = 50% × (instalment interest − the lesser of $1,000 or 25% of instalment interest if all instalments had been made)

The instalment penalty is in addition to the instalment interest — compounding the cost of missing instalment payments. For Mississauga self-employed individuals with large incomes, missing quarterly instalments can trigger both interest AND penalties.

Corporate Tax Instalments

Canadian private corporations must also pay corporate tax in instalments — monthly (not quarterly). For CCPCs using the SBD:

• Monthly instalment due dates: 2 months after fiscal year end + 1 month intervals thereafter (for the next 12 months)
• For most CCPCs: balance of tax is due 2 months after fiscal year end (3 months for SBD-eligible CCPCs in certain situations)
• Monthly instalment = 1/12 of prior year corporate tax (or estimated current year tax)

Our corporate tax team manages monthly corporate instalment schedules for Mississauga business clients to ensure no instalment interest or penalties. Call 437-872-7399.

Instalment Strategy for Mississauga Self-Employed Individuals

For most Mississauga self-employed individuals, the optimal instalment strategy:

1. Wait for CRA’s instalment reminder (February) showing the no-calculation method amounts
2. Pay exactly the amounts CRA specifies on March 15 and June 15
3. If your income for the current year appears to be significantly LOWER than last year, switch to the current year method for the September 15 and December 15 instalments to reduce over-payment
4. If income appears to be HIGHER, continue paying 25% of prior year tax (CRA will not charge interest as long as you pay the prior year amount)
5. Pay the balance by April 30 when you file your T1

This strategy protects against instalment interest while avoiding over-paying quarterly. Our self-employed tax guide integrates instalment planning with overall self-employment tax strategy.

Frequently Asked Questions

Do I have to pay tax instalments if I file and pay my full balance by April 30?

No — if you pay your full tax liability by April 30, you avoid the instalment PENALTY. However, you may still owe instalment INTEREST for the period from each instalment due date (March 15, June 15, September 15, December 15) to April 30, calculated on the shortfall compared to the instalment amounts you should have paid. Many self-employed Canadians are surprised to find CRA charging instalment interest even though they paid everything by April 30 — the interest arises from the quarterly shortfall even if the April 30 balance is paid in full. Pathak Professional Corporation calculates each client’s instalment interest exposure and advises on the minimum quarterly payment to avoid interest. Call 437-872-7399.

Can I pay extra instalments to avoid a large balance due on April 30?

Yes — you can pay more than the minimum instalment at any time. Paying extra instalments reduces the April 30 balance and reduces any potential instalment interest on underpayments in prior quarters. However, there is no benefit to overpaying instalments beyond your estimated total tax owing — overpaid instalments are refunded when you file your T1, but you lose the use of that money in the meantime. The optimal strategy is to pay the minimum required to avoid instalment interest (the no-calculation method or prior year method amounts) and reserve the rest for the April 30 payment.

I just became self-employed this year — do I need to pay instalments?

No — the instalment requirement applies only when you owed more than $3,000 in BOTH of the last two years. In your first year of self-employment, you have not previously owed more than $3,000 from self-employment, so instalments are NOT required. You simply pay your full tax balance by April 30. In your second year of self-employment, if your first year’s tax owing exceeded $3,000, you begin the instalment requirement (because only one year exceeded the threshold — the second year of the two-year rule). You begin MANDATORY quarterly instalments in your THIRD year (when you have two consecutive years exceeding $3,000 owing). However, you can voluntarily pay instalments in year 2 to spread the cash flow impact. Call Pathak Professional Corporation to plan your first-year-of-self-employment tax obligations. Call 437-872-7399.

How do I pay tax instalments to CRA?

CRA tax instalments can be paid through: CRA My Account (online banking payment setup); your bank’s bill payment system (add “CRA Personal Tax Instalments” as a payee using your SIN); mailed cheque to CRA with your remittance voucher (from the instalment reminder letter or Form INNS3); or in person at a Canadian financial institution with a remittance voucher. Use the voucher numbers from CRA’s instalment reminder to ensure your payments are applied to the correct quarter. Never pay instalments without the correct remittance reference — misapplied payments can trigger instalment interest even if you paid the full amount. Pathak Professional Corporation helps Mississauga clients set up CRA instalment payment systems correctly. Call 437-872-7399.

Tax Instalment Help in Mississauga

Pathak Professional Corporation provides tax instalment planning for Mississauga self-employed individuals, investors, retirees, and business owners: determining instalment obligation, calculating optimal quarterly payments, setting up payment systems, and managing the April 30 balance to minimize instalment interest and penalties.

Call 437-872-7399 or email info@pathakcpa.ca. 48 Village Centre Place, Mississauga, Ontario L4Z 1V9.