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Post-Judgment Interest in Ontario: How It's Calculated and Why It Matters

How post-judgment interest works on an unpaid Ontario court judgment, how the rate is set, and why it keeps growing until you actually collect.

Litigation6 min readTSLBy the Treadstone Law team · OntarioUpdated 2026-07
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Key takeaways
  • Under the Courts of Justice Act, a money judgment generally earns interest automatically from the date it is granted until it is paid in full.
  • The postjudgment interest rate is not a number that Ontario sets once and leaves alone.
  • Both rates are set by the same general mechanism, but they are calculated over different time windows and can differ from one another depending on when each rate was fixed.

You finally have a judgment in your favour, but the debtor still has not paid. Does the amount you are owed just sit still while you chase down payment, or does it keep growing? In Ontario, it keeps growing. Post-judgment interest accrues automatically on most money judgments from the day they are issued until the day they are actually paid, and understanding how it works can change how you think about the pace of enforcement.

This article explains what post-judgment interest is, how the rate is set, how it differs from pre-judgment interest, and what it means practically for a creditor trying to collect.

What Post-Judgment Interest Is

Under the Courts of Justice Act, a money judgment generally earns interest automatically from the date it is granted until it is paid in full. This is separate from — and comes after — prejudgment interest, which compensates a plaintiff for the period between when the claim arose and when judgment was granted.

Together, the two forms of interest are meant to reflect the simple reality that money owed today is worth more than the same amount paid years later. Without post-judgment interest, a debtor would have a financial incentive to delay payment for as long as possible, since a dollar owed would never grow while sitting unpaid.

How the Rate Is Set

The postjudgment interest rate is not a number that Ontario sets once and leaves alone. It is fixed under the Courts of Justice Act and adjusted periodically by the province — meaning the rate that applied to a judgment issued a year ago may not be the same rate applying to interest accruing today.

This matters for two reasons:

  1. You cannot assume last year's rate is still current. If you are calculating what a debtor now owes, or negotiating a payoff figure, you need the rate that was in effect for the relevant period, not whatever number you last remember.
  2. The rate can differ across the life of a single judgment. If a debt has been outstanding for a long time, the applicable postjudgment rate may have changed partway through, meaning the calculation is not always a simple single-rate multiplication.

As a general illustration only — as of mid-2026 the published postjudgment rate has been running in the low single digits, but this figure is reset on a regular schedule and must be verified against the current provincial rate table before you rely on it for any actual calculation, demand letter, or settlement negotiation.

Post-Judgment vs. Pre-Judgment Interest

Pre-Judgment InterestPost-Judgment Interest
When it appliesFrom when the claim arose to the date of judgmentFrom the date of judgment until paid in full
Statutory basisCourts of Justice Act, s. 128Courts of Justice Act, s. 129
PurposeCompensates for the delay in getting to judgmentDiscourages delay in paying once judgment exists
RateSet periodically, tied to the quarter in which the lawsuit was startedSet periodically, tied to the judgment date and the period interest accrues

Both rates are set by the same general mechanism, but they are calculated over different time windows and can differ from one another depending on when each rate was fixed.

Why This Matters for Enforcement Strategy

Understanding post-judgment interest changes how creditors sometimes approach collection:

A Practical Note on Collecting the Interest

Post-judgment interest is not usually a separate line item you have to sue for again — it is built into what the judgment allows you to enforce. When you pursue enforcement tools such as garnishment or a writ of seizure and sale, the amount you are entitled to collect includes the accrued interest, calculated up to the relevant date. Getting that calculation right matters, because enforcement paperwork generally has to state a specific dollar figure, and an error can slow down the process or invite a dispute from the debtor.

Frequently asked questions

Does post-judgment interest apply automatically, or do I have to ask for it in my claim?

It generally applies automatically to a money judgment under the Courts of Justice Act, without needing a separate order. Some judgments may specify different terms, so it is worth checking the exact wording of your judgment.

Can a court order a different interest rate than the standard one?

Courts have some discretion in specific circumstances to order a different rate than the standard statutory one, particularly where the standard rate would be clearly unfair given the facts. This is not the norm, but it is possible.

Does interest keep accruing even while I am trying to enforce the judgment?

Yes. Interest continues to accrue until the debt is actually paid, regardless of how long enforcement steps like garnishment or a writ of seizure and sale take to produce payment.

How do I find the current post-judgment interest rate?

The rate is published and updated periodically by the province. Because it changes, always confirm the current published figure before relying on it for a demand letter, settlement calculation, or enforcement document, rather than relying on a number you saw previously.

This article is general information, not legal advice. Reading it does not create a lawyer-client relationship. Ontario laws, tax rates, and government programs change, and how the law applies depends on your specific facts. For advice about your situation, speak with a licensed Ontario lawyer. Treadstone Law is licensed by the Law Society of Ontario — reach us at 1-844-900-1070 or start a file online.

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