Tax Instalments: Who Pays and How to Avoid CRA Interest

If you have income that no one withholds tax from — self-employment earnings, rental profits, investment income, or a pension without enough tax taken off — the Canada Revenue Agency expects you to pre-pay your tax in quarterly chunks rather than in one lump sum next April. Understanding tax instalments in Canada matters because the CRA charges interest, and sometimes a penalty, when required payments arrive late or short. The good news is that the rules are mechanical once you know them, and a little planning keeps you well clear of trouble.

Who has to pay tax instalments in Canada?

You are required to pay by instalments if your net tax owing is more than $3,000 (or more than $1,800 if you are a Quebec resident) in the current year and in either of the two previous years. Net tax owing is roughly the balance you would owe on your return after subtracting tax already withheld and refundable credits — not your total tax bill. In plain terms, the CRA is looking for a pattern: if you have consistently ended the year owing a meaningful amount, it wants that tax spread across the year, the same way an employee has tax taken off every paycheque.

Common situations that push people into instalments include running an unincorporated business, earning significant rental or investment income, drawing a pension or annuity without enough tax withheld, or receiving large one-time income. The CRA typically mails an instalment reminder in February and August to people it expects to owe. Receiving one is a strong signal — but the legal test is the dollar thresholds above, not the letter.

When are the payments due?

For individuals, personal instalments are due four times a year: March 15, June 15, September 15 and December 15. If a date lands on a weekend or a public holiday, your payment is on time if the CRA receives it on the next business day. Self-employed farmers and fishers are an exception — they make a single instalment by December 31 covering two-thirds of their estimated tax.

Corporations are on a different schedule. Most corporations pay monthly instalments, while eligible small Canadian-controlled private corporations with a clean compliance record can pay quarterly. Corporate due dates are tied to your fiscal year-end rather than the calendar, so a corporation with a June 30 year-end will not share the personal dates above. If you draw income both personally and through a company, it is worth tracking the two streams of payments separately so neither slips.

How the CRA calculates your instalments

There are three accepted methods, and you may use whichever produces the smallest required payment without triggering interest.

1. The no-calculation option

This is the amount printed on your CRA instalment reminder. The CRA estimates it from your two most recent returns. If your income is stable year over year, simply paying these amounts on time guarantees you will not be charged instalment interest — even if you end up owing a bit more at filing.

2. The prior-year option

You base your payments on last year's net tax owing, divided into four equal amounts. This works well when this year's income is similar to last year's but your two-year-old return (which the no-calculation method leans on) was unusually high.

3. The current-year option

You estimate this year's net tax owing and pay one-quarter each quarter. This is the best choice when your income has dropped — say a business slowed or you sold a property last year that will not repeat. It carries the most risk: if you underestimate, the CRA charges interest as though you had paid too little.

Paying the amount on your CRA reminder, on time, is the one move that is guaranteed to shut off instalment interest — even if your final bill turns out higher.

Instalment interest and how it adds up

When you skip a payment, pay late, or pay too little, the CRA charges instalment interest, compounded daily, at the prescribed rate for overdue amounts. That rate is reviewed quarterly; for the third quarter of 2026 it sits at 7%. Interest runs from the day the instalment was due until the day you actually pay it or until your balance-due date, whichever comes first.

There is a helpful wrinkle: the CRA calculates interest on a net basis. If you overpay or pay early on one instalment, you earn offsetting instalment interest (credit) that can cancel out a later shortfall. This is why a common recovery strategy for a missed payment is to catch up as soon as possible and, where cash allows, pay the next instalment a little early.

The instalment penalty

A separate penalty applies only when your instalment interest for the year is more than $1,000. The penalty is 50% of the amount by which your instalment interest exceeds the greater of $1,000 or 25% of the instalment interest you would have owed had you made no payments at all. In practice, the penalty only bites when someone ignores their instalments almost entirely — but when it lands, it effectively doubles the cost of the mistake on top of the interest itself.

Practical ways to stay onside

• Automate it. Set up pre-authorized debit through CRA My Account, or schedule the four dates as recurring bill payments in your online banking under the "CRA (revenue) — tax instalment" payee.
• Match the method to your year. If your income fell, use the current-year option and stop overpaying; if it is steady, the no-calculation amount is the safe, simple choice.
• Do not pay to your balance owing. Instalments must be made to the instalment account, not your prior-year balance, or the timing may not credit correctly.
• Keep a buffer. If you expect a big one-time gain, set aside the estimated tax immediately rather than scrambling in December.

One more note: paying instalments is not optional just because you would rather settle up in April. Even if you file and pay your full balance on time, the CRA can still charge instalment interest for the quarters you skipped during the year.

Instalments are one of those quiet obligations that cost nothing to get right and quite a lot to get wrong. If you are unsure which calculation method fits your year, whether a one-time gain has tipped you over the threshold, or how corporate and personal instalments should be coordinated, we can map it out with you. Book a consultation or learn more about our corporate tax services, and we will make sure your payments are right-sized and on time.

This article is general information, not tax, legal, or financial advice. Rules and figures are current as of 2026 and can change. Please confirm your own situation with Lewis Partners.