The New Zealand Financial Markets Authority (FMA) has issued a warning to Kiwibank for failing to apply age-based transaction fee waivers to certain joint account customers, resulting in customers being overcharged and raising concerns under the fair dealing provisions of the Financial Markets Conduct Act 2013. Different versions of Kiwibank’s Fees and Limits brochures from approximately March 2005 to November 2024 indicated transaction fees would be waived on certain accounts where customers were under 18 or 19 years of age, or over 65. However, since at least 2011 Kiwibank charged fees on joint accounts where the secondary account holder met the age criteria but the primary account holder did not, contributing to overcharging 8,663 customers a total of NZD 912,053.79 between July 2011 and November 2024. For the period after 1 April 2014, the FMA considers the fee charges shown in account statements were, or were likely to be, false or misleading representations that Kiwibank had the right to charge the fees when it did not. The FMA cited two main root causes: inconsistent internal understanding of how the waiver should apply to joint accounts and a system limitation that only applied the waiver based on the primary account holder’s age; Kiwibank investigated the issue after a June 2023 complaint, self-reported to the FMA in August 2024, and remediated affected customers including use-of-money interest.