The December 15 CRA Instalment: How Much to Pay, and Whether You Have To (2026)

December 15, 2026 is the last CRA instalment date for 2026. If your August reminder showed a December amount, paying exactly that amount by December 15 (with your earlier 2026 reminder amounts also paid on time) means the CRA has no shortfall to charge instalment interest on, even if your real 2026 tax turns out higher. If you pay less than required, interest on the shortfall is 7% for October to December 2026, compounded daily. Anything still owing for 2026 is due April 30, 2027. Below is how to tell whether December applies to you, where the number comes from, and what paying less really costs, using CRA rules as of October 2026.

Quick answer

• Who pays: people whose net tax owing is more than $3,000 ($1,800 in Québec) for 2026 and for either 2025 or 2024.
• How much: the December figure on your August 2026 instalment reminder. If your August reminder was your only 2026 reminder and you use the prior-year or current-year option instead, it's 25% of that option's total.
• If short: 7% a year on the shortfall for October 1 to December 31, 2026, compounded daily. The Q1 2027 rate isn't published yet.
• Deadline: Tuesday, December 15, 2026. A pre-authorized debit has to be set up at least 5 business days earlier, so by December 8.

Do you owe a December instalment at all?

The CRA's two-year test: you have to pay 2026 instalments if your net tax owing is more than $3,000 ($1,800 for Québec residents) in 2026 and in either 2025 or 2024 (Canada Revenue Agency). Both parts have to be true. Your province or territory of residence on December 31 decides which threshold applies.

A reminder doesn't settle the question. The CRA sends reminders to people who will likely have to pay, and says plainly that if you received one but your 2026 net tax owing is $3,000 or less ($1,800 or less in Québec), you don't have to pay instalments for 2026. If your income dropped this year, that matters for December.

One exception: if your main income is self-employment from farming or fishing, you have a single instalment date, December 31, with a reminder in November, not the quarterly dates.

For a plain-language look at what the reminder is and isn't, see why a CRA instalment reminder is not a bill. Québec residents can walk through the lower threshold in our Québec $1,800 guide.

Where the December amount comes from

The CRA sends two instalment reminders (form INNS1) a year: the February reminder covers March and June, and the August reminder covers September and December. You can also see them in your CRA account. The December number you're looking at came in August.

You can pay that amount or work out your own using one of the CRA's other two options. If your August reminder doesn't mention a March or June 2026 instalment payment, the CRA sets the split like this:

Option	How the total is set	December 15 payment
No-calculation	The CRA works it out from your latest assessed return and prints it on the reminder	The amount in box 2 of your August reminder
Prior-year	Your 2025 net tax owing, plus CPP contributions payable and any voluntary EI premiums	25% of the total (75% was due September 15)
Current-year	Your estimated 2026 net tax owing, plus CPP contributions payable and any voluntary EI premiums	25% of the total (75% was due September 15)

Our CRA instalment calculator runs the prior-year and current-year numbers if you'd rather check your own figure against the reminder.

Why paying the reminder amount protects you

The CRA calculates instalment interest "based on the payment calculation option that results in the least amount of interest" (Canada Revenue Agency). The reminder amount is the no-calculation option. If you paid every 2026 reminder amount in full by its due date, that option shows no shortfall, so there's nothing for instalment interest to accrue on, even if your actual 2026 tax turns out higher. (This follows from the CRA's formula; it isn't a separate rule.)

It doesn't make the tax go away. Instalments are prepayments of the tax you would otherwise pay in one lump sum on April 30 of the following year, so any 2026 tax beyond what you paid in instalments is simply due by April 30, 2027. Paying the reminder amount on time just means that balance carries no instalment interest.

Paying less than the reminder: the trade-off at 7%

Paying less is allowed. If you received an August reminder only, the CRA says you can reduce or stop 2026 instalments if what you've already paid will cover your estimated 2026 net tax owing, or if that net tax owing will be $3,000 or less ($1,800 or less in Québec). For the prior-year and current-year options, the CRA will not charge instalment interest or a penalty if you pay in full by the due dates, "unless your estimated instalment amounts are too low" (Canada Revenue Agency).

If your estimate does turn out too low, the cost is interest, not a fine:

• The rate: the CRA prescribed rate on overdue taxes, CPP contributions and EI premiums is 7% for October 1 to December 31, 2026, per the CRA's Q4 2026 rate page dated August 28, 2026. Instalment interest is compounded daily, and the rate can change every three months.
• The period: interest runs from the instalment's due date to your balance due date. For December 15 that's 16 days in 2026, then the days in 2027 up to April 30. The Q1 2027 rate wasn't published as of October 7, 2026.
• The small-charge floor: the CRA's own formula shows the charge applies when it's more than $25.
• The penalty: it applies only if your total 2026 instalment interest is more than $1,000. Then the CRA subtracts the greater of $1,000 or 25% of the interest you'd have paid with no instalments at all, and halves the difference.

A worked example

Say you paid September in full, your December reminder shows $2,400, and you pay $1,400 because you expect 2026 to come in lower. It doesn't, and the $1,000 shortfall stands. These figures are our own approximation (7% ÷ 365, compounded daily), not a CRA calculation:

Item	Amount
Shortfall on December 15, 2026	$1,000
Interest for December 15 to 31, 2026 (16 days at the confirmed 7%)	≈ $3.07
Interest to April 30, 2027 (136 days), assuming 7% continues into 2027	≈ $26.42
Instalment penalty	None (far below the $1,000 interest threshold)

The 2027 part is an illustration: the rate for those days isn't set yet. If your 2026 tax really is lower than the reminder assumed, the CRA's least-interest rule can measure you against that lower figure (the current-year option), and the shortfall shrinks or disappears.

December can offset a short September

If September 15 was missed or short, December is your chance to soften it. The CRA says you can reduce or eliminate instalment interest and penalties by overpaying your next instalment or paying it early, which earns instalment credit interest (Canada Revenue Agency). The credit only goes one way: it is not refundable, and it can only be used against interest charges on late or short payments for the same tax year.

So paying December a few weeks early, or a little above the required amount, earns credit that nets against interest building on a short September. If September is still unpaid, our September 15 catch-up guide walks through the order to do things in.

VRITTI is a Canadian iOS app for self-employed people that keeps a running estimate of the CRA's share as income lands, so December 15 is a date you've already saved for rather than a number you go looking for. VRITTI sets this aside for your province as income lands, and it's coming soon: join the waitlist. For the bigger picture on self-employed tax, start with our guide to self-employed taxes in Canada.

Paying by December 15

December 15, 2026 is a Tuesday, so the weekend rule (a payment received on the next business day counts as on time) doesn't come into play this year. The CRA's payment options for individuals:

• Online banking: some banks and credit unions let you add the CRA as a payee and make single or scheduled payments.
• CRA My Payment: debit card only. The CRA is explicit that credit cards can't be used with My Payment.
• Pre-authorized debit: set up in your CRA account, scheduled at least 5 business days before the withdrawal. For a December 15 withdrawal, that means by December 8 (our own date count).
• Credit card: only through third-party service providers, which charge their own fees.
• In person at Canada Post: you need a customized QR code first. For in-person or mail payments, use your instalment remittance voucher (form INNS3).

The CRA doesn't send a receipt right away. Keep proof of payment, and allow 3 business days for an online payment (10 for a cheque) before checking that it shows in your CRA account. Paying a few business days before December 15 keeps the whole thing calm.

Sources

• CRA: Required tax instalments for individuals (two-year test; instalments cover tax normally paid on April 30 of the following year)
• CRA: Payment due dates (March 15, June 15, September 15, December 15; next-business-day rule; farmers and fishers, December 31)
• CRA: Who has to pay ($3,000 / $1,800 Québec thresholds; February and August reminders; August-reminder-only amounts and the 75% / 25% split; reducing or stopping instalments)
• CRA: Options to calculate (no-calculation, prior-year, current-year)
• CRA: Interest and penalty charges (daily compounding; least-interest option; $25 charge floor; credit interest; $1,000 penalty threshold and formula)
• CRA: Prescribed interest rates, fourth calendar quarter 2026 (7% on overdue amounts, October 1 to December 31, 2026)
• CRA: Make a payment (online banking; My Payment debit only; pre-authorized debit at least 5 business days ahead; third-party credit card providers; Canada Post QR code)
• CRA: How to pay instalments (remittance voucher INNS3; allow 3 or 10 business days before confirming)

Last verified: October 7, 2026, against the canada.ca pages above. The Q1 2027 prescribed rate had not been published on that date.

This article explains CRA rules in plain language. It's an estimate, not advice: general information, not tax advice for your situation. Thresholds, rates and dates change; check the current CRA page before relying on a number.