In 1990, during the discussions on the Usury Act Amendment Bill, the then Registrar of the Usury Act, Mr. Herman le Roux, informed the committee that several financial institutions were still calculating interest in advance, despite the original Usury Act of 1968 clearly stating that interest must be calculated in arrears—that is, at the end of the period. In a letter dated 6 December 1990, the Deputy Registrar of Banks and Building Societies at the South African Reserve Bank, Mr. C.F. Wiese, notified all financial institutions that it had been established—following a directive from the Minister of Finance—that some institutions were contravening the provisions of the Usury Act by calculating interest on loans repayable in regular instalments incorrectly. He emphasized that interest may not be calculated in advance without adjusting for payments received before the due date. Following this instruction, all banks were required to convert to the correct interest rate methodology—interest in arrears.

Recently, financial investigating consultant Emerald van Zyl discovered that some banks financing vehicle loan accounts continue to calculate interest in advance, resulting in clients being overcharged significant amounts. In one recent case involving Toyota Financial Services, a division of WesBank, the overcharges amounted to R110,000. It was further found that interest calculated in advance over a 72-month loan period was overstated by R20,000, prompting the matter to be referred to the National Financial Ombud Scheme (NFO) for investigation.