Quarterly Tax Instalments in Canada: The Complete Guide for Self-Employed Workers (2026)

If you're self-employed in Canada and owe more than $3,000 in tax, CRA expects you to pay throughout the year — not just at tax time. Here's exactly how quarterly instalments work, how much you owe, and how to pay the least amount legally possible.

When you're an employee, your employer withholds income tax from every paycheque. But when you're a freelancer, contractor, or sole proprietor, nobody withholds tax for you. That means you could owe a massive lump sum in April — and CRA doesn't want to wait.

Enter quarterly tax instalments: prepayments you make four times a year to cover your expected tax bill. Get them right, and you'll avoid interest charges and surprise bills. Get them wrong, and CRA compounds daily interest on the shortfall.

This guide covers everything you need to know.

Do You Need to Pay Quarterly Instalments?

Not every self-employed person needs to pay instalments. Here's the rule:

"Net tax owing" means your total tax payable minus amounts withheld at source (like from a T4). It includes:

• Federal and provincial income tax
• CPP contributions (both the employee and employer portions for self-employed)
• Any other amounts payable (Old Age Security clawback, etc.)

Quick Check: Am I Over $3,000?

Here's a rough estimate for a freelancer in Ontario with no other income:

As you can see, most full-time freelancers earning over $30,000 will cross the threshold once you factor in CPP contributions.

When Are Instalments Due?

CRA requires four payments per year, all on the 15th:

If the 15th falls on a weekend or statutory holiday, the deadline extends to the next business day.

The Three Calculation Methods (Pick the Cheapest)

CRA offers three ways to calculate your quarterly payments. You're allowed to use whichever method results in the lowest payment — and CRA won't charge instalment interest as long as you meet the requirements of at least one method.

Method 1: Current-Year Method

Estimate your current year's net tax owing and divide by four.

Best when: Your income is dropping compared to last year. If you earned $100K last year but only expect $60K this year, this method saves you money.

Risk: If you underestimate, CRA charges interest on the shortfall. You need to be reasonably accurate.

Method 2: Prior-Year Method

Use last year's actual net tax owing (from your Notice of Assessment) and divide by four.

Best when: Your income is stable year over year. Simple and safe — no estimating required.

Risk: If your income is growing fast, you'll owe a lump sum at tax time (but no interest penalty since you used an approved method).

Method 3: No-Calculation Option

Use the amounts CRA tells you on your instalment reminder (Form INNS1 or INNS2). CRA calculates this using a combination of your two prior years.

How it works:

• Q1 and Q2: Based on your tax owing from two years ago
• Q3 and Q4: Adjusted based on last year's actual tax, minus what you already paid in Q1+Q2

Best when: You don't want to think about it. Just pay what CRA says.

Which Method Should You Use?

A Real Example: Sarah the Freelance Designer

Let's walk through a concrete example.

Sarah's situation:

• Freelance graphic designer in Ontario
• 2024 net self-employment income: $80,000
• 2024 tax + CPP owing: $18,500
• 2025 estimated income: $70,000 (lost a client)
• 2025 estimated tax + CPP: $15,200

Comparing the Three Methods:

Sarah should use the current-year method — it saves her $3,300 compared to the prior-year method. Since her income is genuinely dropping, she can confidently estimate lower.

What Happens If You Don't Pay (or Pay Late)?

CRA charges compound daily interest on late or insufficient instalment payments. Here's what you need to know:

• Interest rate: The prescribed rate changes quarterly. For 2025, it's approximately 8-10% (this is high by historical standards).
• Calculation period: Interest runs from the instalment due date to the earlier of: the date you pay, or April 30 of the following year.
• Netting: CRA nets your instalment interest. If you overpay one quarter, it offsets underpayment in another.
• No penalty: Unlike late-filing penalties, there's no additional penalty for late instalments — just interest. But the interest adds up fast at 9%+.

How Much Could Interest Cost You?

Let's say you owe $5,000 per quarter and miss the March 15 payment entirely:

Missing all four quarterly payments on a $20,000 annual obligation could cost you over $1,000 in interest alone.

How to Actually Pay CRA Instalments

You have several payment options:

1. Online Banking (Easiest)

1. Log into your bank's online portal
2. Add "CRA - Tax Instalments / Acomptes provisionnels" as a payee
3. Use your Social Insurance Number (SIN) as the account number
4. Set up the payment amount and date

💡 Pro tip: Set up recurring payments on the 10th of March, June, September, and December. This gives a 5-day buffer before the due date.

2. CRA My Payment Portal

Pay by credit card or Visa Debit at CRA My Payment. Note: credit card payments may incur a processing fee from your card provider.

3. Pre-Authorized Debit (Set and Forget)

Set up through CRA My Account. CRA automatically debits your bank account on each due date. This is the best option if you want zero admin.

4. At Your Bank

Visit any major bank branch with a personalized instalment remittance voucher (from your CRA instalment reminder).

5 Strategies to Minimize Your Instalments

1. Maximize Business Deductions

Every dollar of legitimate business deductions reduces your net income and, therefore, your instalment amounts. Track expenses religiously. Claim your home office deduction. Don't leave money on the table.

2. Use the Current-Year Method When Income Drops

If you lose a client or take time off, switch to the current-year method immediately. You can reduce payments for the remaining quarters.

3. Incorporate (When It Makes Sense)

Once you're earning above ~$100K, incorporating and paying yourself a salary means tax gets withheld at source — potentially eliminating the need for instalments entirely. Consult a CPA to run the numbers.

4. Contribute to RRSPs Before Year-End

RRSP contributions reduce your taxable income, which reduces your tax owing, which reduces next year's instalment requirement. A $10,000 RRSP contribution could reduce your instalments by $750-1,200/year.

5. Time Large Expenses Strategically

If you're buying equipment or making capital expenditures, timing them before December 31 means you can claim CCA (depreciation) that tax year, reducing your instalment base for the following year.

Common Mistakes to Avoid

1. Ignoring instalment reminders. CRA sends reminders (INNS1/INNS2) — don't throw them out. They contain your recommended payment amounts.
2. Forgetting CPP in your calculation. Self-employed CPP is both halves (11.90% in 2025), and it's a huge addition to your tax bill. A freelancer earning $70K pays ~$7,800 in CPP alone.
3. Not adjusting mid-year. If your income changes significantly, recalculate. You can adjust Q3 and Q4 payments even if Q1 and Q2 are already paid.
4. Using the wrong year's numbers. Make sure you're using the correct tax year for each method. Prior-year means last year's Notice of Assessment, not two years ago.
5. Paying the wrong CRA account. Ensure your payment goes to "Tax Instalments" — not "Balance Owing" or "GST/HST." These are separate accounts.

Instalments vs. HST Remittances: Don't Confuse Them

A common source of confusion: income tax instalments and HST/GST remittances are completely separate obligations.

If you're collecting HST, you need to track and remit that separately. Our HST/GST Tracker handles the sales tax side.

Key Takeaways

• $3,000 threshold: If your net tax owing exceeds $3,000 in the current year and a prior year, you must pay quarterly instalments.
• Four due dates: March 15, June 15, September 15, December 15.
• Three methods: Current-year, prior-year, and no-calculation. Use whichever gives you the lowest payment.
• Interest is costly: At ~9%, missing payments adds up fast. Set up auto-payments.
• CPP matters: Don't forget to include self-employed CPP (both halves) in your calculation.
• You can adjust mid-year: If income changes, recalculate Q3 and Q4.

Quarterly instalments feel like an extra burden, but they're really just forced savings for your tax bill. Once you set up automatic payments, you'll never think about them again — and you'll avoid that painful lump sum in April.

Need help calculating your exact instalment amount? Our Quarterly Instalment Calculator ($15) compares all three methods and gives you the answer in seconds.

📖 Related: Every 2026 Tax Deadline for Self-Employed Canadians · Free Expense Categorizer