Making Sense of CRA Tax Instalments

Making Sense of CRA Tax Instalments (Corporate & Personal)

If you run a small business or own a corporation, the CRA expects you to pay your taxes throughout the year — not just in April. Missing those deadlines can trigger steep interest and penalties. Here is a plain-English guide to who pays, when, and how to estimate your own instalments if you are just starting out.

If you are a salaried employee, your income tax is deducted from every paycheque before you see the money. But if you are a small business owner, a freelancer, or an incorporated professional, the Canada Revenue Agency (CRA) expects you to manage that process yourself — through tax instalments.

Instalments are simply partial payments of your total annual tax bill, made throughout the year while you are earning the income. They catch many new business owners off guard, and ignoring them can be an expensive mistake. Here is a plain-English guide to how they work.

The $3,000 Threshold

The trigger for personal tax instalments is straightforward: if your net tax owing (the amount you owe when you file your return, after any source deductions) is more than $3,000 for the current year, and was also more than $3,000 in either of the two previous years, you are required to pay by instalment.

For corporations, the same $3,000 threshold applies, but the payment schedule is more frequent. The key takeaway is this: if you owe more than $3,000 at tax time, expect the CRA to ask for instalments the following year.

Personal vs. Corporate Due Dates

The schedule you follow depends on whether you are paying personal taxes (including sole proprietorships) or corporate taxes.

Note: To qualify for quarterly corporate instalments, your Canadian-controlled private corporation (CCPC) must meet specific eligibility criteria, including a clean compliance history and taxable income under $500,000. If you are unsure which schedule applies to your corporation, your CPA can confirm this quickly.

How to Calculate Your Instalments

If you receive an instalment reminder from the CRA, the easiest and safest option is simply to pay the amount on the notice. The CRA calculates this figure based on your previous tax returns. If you pay the exact amounts on the reminder by the due dates, the CRA will not charge you any interest or penalties — even if your actual tax bill ends up being higher.

What if my income has dropped significantly?

If you know your income will be substantially lower this year, you are not locked into the CRA's reminder amounts. You can calculate your instalments based on your estimated current-year tax instead. This is a legitimate strategy — but it comes with risk. If you underestimate and underpay, the CRA will charge interest and penalties on the shortfall. I generally recommend this approach only when the income reduction is significant and well-documented.

What if I have a new corporation?

New corporations receive a grace period: you are not required to make instalment payments during your first year of operation. However, your full tax balance is still due on your corporation's balance-due day (generally two months after your fiscal year end, or three months if you qualify as a small CCPC).

The Cost of Ignoring Instalments

The CRA does not treat instalments as optional. If you are required to pay and you fail to do so — or if you pay late — the consequences can be significant.

First, the CRA charges instalment interest, compounded daily. The prescribed rate is set quarterly at the base rate plus 4%, which in recent years has resulted in effective annual rates of 7% to 9% or more. This interest accrues from the original due date, not from when you file your return.

Second, if your total instalment interest for the year exceeds $1,000, the CRA also applies an instalment penalty. The calculation is steep: they take 25% of the interest you would have owed if you had made no payments at all, subtract $1,000, and divide the remainder by two. On a large underpayment, this can add up quickly.

How Your CPA Helps

Managing cash flow to meet quarterly or monthly tax obligations is one of the most common challenges I see in small business clients. At Simplicity Tax, reviewing your corporate and personal tax exposure is a standard part of our quarterly check-ins. If your income is tracking lower than the CRA expects, we can safely adjust your instalment payments down. If you are having a strong year, we make sure you are setting aside enough to avoid a painful surprise at filing time.

For clients handling their own bare-bones T2 filings, the rule of thumb above is a reasonable starting point — but even a single planning conversation can save you significantly more than it costs.