Does interest keep adding up on a court judgment in Ontario after it is issued?

Yes. Once a court judgment is issued in Ontario, the unpaid amount begins to accrue post-judgment interest under the Courts of Justice Act. The rate is set by regulation and is updated periodically; it applies automatically without the need for a separate court order.

Post-judgment interest means that the longer a judgment remains unsatisfied, the total amount owed grows. For large judgments or extended enforcement periods, this can add meaningfully to the total the debtor must pay. It also has a practical effect in enforcement: when you garnish wages or a bank account, the garnished amounts go toward the total judgment debt including accrued interest, so the final payment to clear the debt will be larger than the original judgment amount alone.

Costs awards — when the court orders the losing party to pay a portion of the winning party's legal fees and disbursements — also attract post-judgment interest from the date the order is made, or from the date the costs are assessed, depending on the circumstances.

There is also prejudgment interest, which accrues from the date the cause of action arose until the date of judgment, and which must be requested as part of your claim. Combined, prejudgment and post-judgment interest can represent a significant portion of the total recovery, particularly in disputes that take years to resolve.

Make sure your enforcement calculations include all accrued interest to ensure you collect the full amount owed.