Post-Judgment Interest in the Northern Territory

Interest Keeps Running After the Order

Once your NTCAT monetary order is registered as a Local Court judgment, interest accrues on the unpaid balance. This isn't a penalty you have to ask for — it's a statutory entitlement that compensates you for the time value of money the debtor should have paid.

Many creditors either forget to claim post-judgment interest or don't know how to calculate it, leaving money on the table with every enforcement application.

The Applicable Rate

Post-judgment interest is governed by Part 39 of the Local Court (Civil Jurisdiction) Rules 1998. Under rule 39.01, interest runs from the date of judgment unless the Court orders otherwise. The rate is set under rule 59.02 of the Supreme Court Rules: it is 10.35% from 1 July to 31 December 2026 (and was 9.60% from 1 January to 30 June 2026).

For a registered NTCAT order, use the judgment date recorded by the Local Court; do not assume interest starts on the NTCAT payment due date.

How to Calculate It

The basic formula is straightforward:

For each rate/payment period: Interest = Outstanding principal × Annual rate × (Days in period ÷ 365); add the period amounts for the total.

Work through it step by step:

1. Start with the judgment amount and track recoverable enforcement costs and payments separately
2. Split the calculation at each payment date and interest-rate change
3. Apply each payment first to recoverable enforcement costs, then accrued interest, and then principal
4. For each period, multiply the outstanding principal by the applicable annual rate and by the days in that period divided by 365; add the period amounts

If the debtor has made partial payments at irregular intervals, you'll need to recalculate the interest for each period between payments, adjusting the principal balance each time.

Adding Interest to Enforcement Applications

When you file an enforcement application — an attachment order, a warrant of seizure and sale, an examination summons — the total amount you're seeking should include:

• The original judgment amount
• Minus any payments received
• Plus accrued post-judgment interest
• Plus recoverable enforcement costs (court filing fees, bailiff charges)

State the interest calculation clearly in your supporting affidavit. Courts expect to see the rate used, the period covered, and the resulting figure. An unexplained lump sum invites objection.

Common Mistakes

Using the wrong start date. Interest runs from the date of judgment unless the Court orders otherwise, not from when the original dispute arose. For an NTCAT order registered in the Local Court, use the judgment date recorded by the Local Court.

Ignoring payment allocation. Apply payments first to recoverable enforcement costs, then accrued interest, and only then principal. A $500 payment may therefore leave the interest-bearing principal unchanged if costs and accrued interest absorb it.

Rounding errors. Small rounding mistakes compound over twelve years of potential enforcement. Use exact figures and show your working.

Why It Matters

On a $5,000 judgment left unpaid for two years, even a modest interest rate adds several hundred dollars to the total debt. Over the full twelve-year enforcement window, the interest component can become substantial. Claiming it correctly ensures you recover the full value of what you're owed.

The Enforcing an NTCAT Order guide includes interest calculation worksheets and examples for both simple and partial-payment scenarios.

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