Maintenance Arrears
Calculator

Add up every instalment that fell due under the maintenance order from the date it started (including any annual increases the order provides for), then subtract everything the other parent actually paid. Payments are normally set off against the oldest unpaid instalments first. What is left is the arrears capital, and interest can be added on each unpaid instalment from the date it was due.

Interest on arrear maintenance can generally be claimed at the prescribed rate of interest from the date each instalment fell due, unless the order sets another rate. The prescribed rate is the Reserve Bank repo rate plus 3.5 percentage points (10.50% a year from 1 July 2026). Ask the maintenance officer or an attorney whether interest should be included in your enforcement application.

Under the in duplum rule, interest stops running once the unpaid interest equals the unpaid capital on which it accrued. This calculator applies that cap to each unpaid instalment.

Arrears under a court order are generally treated as a judgment debt, which prescribes only after 30 years under the Prescription Act. In practice you can usually claim arrears from the date the order took effect. If there was never a court order, past maintenance is a different question: see our guide to retrospective maintenance claims.

Apply to the maintenance court that made the order using Form K (J306), an application for enforcement under section 26 of the Maintenance Act. The court can authorise a warrant of execution against property, an emoluments attachment order against the defaulter's salary, or an attachment of debts owed to them. Not paying maintenance is also a criminal offence under section 31.

No. It is an estimate to help you prepare. The amount recoverable is decided by the court, and the prescribed interest rate has changed several times over the years, while this calculator uses a single rate for the whole period.