Prejudgment Interest Alberta: How It Is Calculated on Civil Claims

When someone owes you money and does not pay, the debt does not sit frozen at the original amount while you wait for a court date. In Alberta, you can claim interest on the money from the date the debt arose until the Justice hands down a judgment. This is called prejudgment interest, and it is governed by the Judgment Interest Act (RSA 2000, c J-1) and the Judgment Interest Regulation (Alta Reg 215/2011).

Contractual vs Statutory Interest

If your contract with the defendant specifies an interest rate — for example, "invoices not paid within 30 days accrue interest at 2% per month" — you can claim that contractual rate. The Justice has discretion to enforce it up to the date of judgment.

If there is no written interest rate in the agreement, you claim statutory interest under the Judgment Interest Act. Statutory rates are prescribed by regulation and change periodically. They are typically lower than commercial rates, but they apply automatically — you do not need a contract clause to claim them.

When Prejudgment Interest Starts

Prejudgment interest accrues from the date the cause of action arose. For most debt claims, that is the date payment was due. For a contractor deposit, it is the date the contractor was supposed to start work (or whenever it became clear they would not). For a property damage claim, it is the date the damage occurred.

Interest runs continuously from that date until the Justice renders a judgment.

Post-Judgment Interest

Once a judgment is entered, a separate clock starts. Post-judgment interest accrues automatically on the unpaid balance from the date of judgment until the full amount is paid. The rate is set by regulation. This matters because enforcement can take months — garnishment orders, asset seizures, and payment plans all take time, and the debtor is paying interest the entire time.

How to Include Interest in Your Claim

When completing the Civil Claim (Form CTS1461), the remedy section should break down your claim: the principal amount, interest claimed to date, and the ongoing daily rate. If you are claiming contractual interest, reference the contract clause. If statutory, you can simply state that you are claiming interest under the Judgment Interest Act.

You do not need to calculate the exact interest up to the trial date when you file. The Justice will do the final calculation at judgment. But showing the breakdown in your claim demonstrates that you have done the math and makes your case easier to assess.

Practical Example

You lent a friend $10,000 on January 1, 2025, with repayment due by March 1, 2025. There was no written interest clause. They never paid. You file a Civil Claim on October 1, 2026 — 19 months after the due date.

At the prescribed statutory rate, prejudgment interest adds up over those 19 months. The amount is not huge on a $10,000 claim — statutory rates are modest — but on a $90,000 claim, the interest over a year or two of waiting for trial can add thousands of dollars to the judgment.

Interest Does Not Count Against the $100,000 Limit

Prejudgment interest and costs are added on top of the principal claim amount. They do not count toward the $100,000 monetary jurisdiction of the Alberta Court of Justice. You can claim $100,000 in principal and the interest accrued on top of that.

The Alberta Civil Claim Guide includes a deadline calendar and interest worksheet to help you track accrual from day one.

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