Euro Blitz 21 (Pty) Ltd and Another v Secena Aircraft Investments CC

The respondent (Secena Aircraft Investments CC) issued summons against the appellants (Euro Blitz 21 (Pty) Ltd and Ivo Branco) in the Germiston Magistrate's Court claiming arrear rental plus interest and costs based on a written lease agreement. The Magistrate's Court granted judgment on 19 February 2009, ordering the appellants to pay the capital amount plus "interest at prime plus 5% calculated daily with effect from 24/03/06 to date of payment." The lease agreement contained clause 21.4 which provided for interest on outstanding amounts "calculated on a daily basis, at a rate of prime plus 5%". Subsequently, the respondent launched application proceedings in the South Gauteng High Court seeking a declarator that the interest in the magistrate's order was to be calculated daily and compounded daily. The High Court (Kolbé AJ) granted the order sought, holding that the words "calculated daily" meant interest was to be compounded daily. The appellants appealed with leave of the court a quo.

• Whether the words 'calculated daily' in the magistrate's court order meant simple or compound interest
• Whether the principles of interpretation applicable to documents apply to court orders
• Under what circumstances compound interest is claimable in South African law
• Whether the in duplum rule applied to the interest calculation

The appeal was upheld with costs. The order of the South Gauteng High Court was set aside and replaced with an order declaring that: (i) Interest which accrues on the capital amount of R353,126.40 may accumulate for the period from 24 March 2006 to 1 June 2012 and the in duplum rule is suspended for such period; (ii) The in duplum rule shall apply to interest which accrues on the capital and accrued interest from 2 June 2012 to date of payment. The respondents were ordered to pay the applicant's costs until delivery of the answering affidavit, jointly and severally, with the remainder of the application dismissed and the applicant to pay the respondents' costs incurred after delivery of the answering affidavit.

The binding legal principles established are: (1) The words "calculated daily" in a court order or contract refer to the method or frequency of calculating interest, not to whether interest is to be compounded. (2) "Calculate" means to determine by mathematical reckoning, while "capitalise/compound" means to convert interest into capital - these are distinct concepts with different legal meanings. (3) Compound interest is claimable only in defined circumstances: where parties expressly agree to pay compound interest; where the obligation to pay compound interest is properly alleged and established by evidence; or where universal custom of charging compound interest is uniformly and universally observed. (4) Where compound interest is not expressly provided for in a written agreement, only simple interest is due. (5) The principles applicable to the interpretation of documents apply equally to the interpretation of court judgments and orders - the court's intention must be ascertained primarily from the language used according to ordinary grammatical meaning unless uncertainty arises.

The court noted that capitalisation of interest is an accounting exercise designed to simplify the calculation of compound interest, and in certain circumstances might amount to a novation thereby converting the interest element into capital. The court also observed that the appellants' version regarding the absence of agreement for compound interest was not disputed in the respondent's replying affidavit, which was significant. The court mentioned that the separate issue pertaining to the applicability of the in duplum rule was conceded in the court a quo and for that reason was not considered by the Supreme Court of Appeal, though the order did address the application of the in duplum rule to the facts.

This case provides important guidance on the interpretation of interest clauses in court orders and contracts. It clarifies the critical distinction between the method of calculating interest and the compounding (capitalisation) of interest. The judgment reinforces the principle that compound interest is not lightly inferred and will only be awarded in defined circumstances. It demonstrates the application of established documentary interpretation principles to court orders. The case serves as authority that the phrase "calculated daily" or similar language referring to the frequency of calculation does not, without more, imply compound interest. This has significant implications for commercial contracts, lease agreements, and the enforcement of debt obligations in South African law.