UMB FINANCIAL CORP

On August 25, 2026, three foundations and trusts that are related interests of Chairman and Chief Executive Officer J. Mariner Kemper adopted a single, pre-arranged stock sale plan in accordance with Rule 10b5-1(c) (Rule 10b5-1) under the Exchange Act for the sale of shares of the Company’s common stock (the 2027 Plan). The 2027 Plan was entered into during an open trading window in accordance with the Company’s requirements regarding transactions in the Company’ssecuritiesand is intended to satisfy the affirmative defense conditions of Rule 10b5-1. The 2027 Plan provides for the monthly sale of an initial number of shares of the Company’s common stock on the first business day of each month. In addition, the 2027 Plan provides for the sale of an additional number of shares once the market price of the Company’s common stock meets or exceeds certain minimum threshold prices as specified in the 2027 Plan. Should the market price of the Company’s shares meet or exceed secondary and tertiary pricing thresholds as specified in the 2027 Plan, up to one and a half and double the initial number of shares in the aggregate may be sold in that month, respectively. Sales under the 2027 Plan may occur beginning in January of 2027 (after conclusion of the applicable cooling off period following adoption of the 2027 Plan) and end no later than December 31, 2027. The aggregate number of shares of common stock of the Company that will be sold under the 2027 Plan will vary depending on the market price achieved but will not exceed a maximum of 105,024 shares in aggregate.