Exhibit 99.1

C123456789 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext 000000000.000000 ext ENDORSEMENT_LINE SACKPACK 000000000.000000 ext 000000000.000000 ext MR A SAMPLE DESIGNATION (IF ANY) ADD 1 Your vote matters – here’s how to vote! 000001 ADD 2 ADD 3 You may vote online or by phone instead of mailing this card. ADD 4 MMMMMMMMM ADD 5 Online ADD 6 Go to www.envisionreports.com/UMBF or scan the QR code — login details are located in the shaded bar below. Phone Call toll free 1-800-652-VOTE (8683) within the USA, US territories and Canada Save paper, time and money! Using a black ink pen, mark your votes with an X as shown in this example. Sign up for electronic delivery at Please do not write outside the designated areas. www.envisionreports.com/UMBF Special Meeting Proxy Card 1234 5678 9012 345 qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE. q A Proposals — The Board of Directors recommends a vote FOR on Proposal 1—3. + For Against Abstain For Against Abstain 1. Proposal to approve an amendment to the UMB articles of 2. Proposal to approve the issuance of UMB common incorporation to increase the number of authorized shares of stock to holders of HTLF common stock pursuant to UMB common stock from eighty million (80,000,000) shares to the merger agreement. one hundred sixty million (160,000,000) shares. 3. Proposal to adjourn or postpone the UMB special meeting, if necessary or appropriate, to solicit additional proxies if, immediately prior to such adjournment or postponement, there are not sufficient votes to approve the UMB articles amendment proposal or the UMB share issuance proposal or to ensure that any supplement or amendment to the accompanying joint proxy statement/prospectus is timely provided to holders of UMB common stock. B Authorized Signatures — This section must be completed for your vote to be counted. — Date and Sign Below Please sign exactly as name(s) appears hereon. Joint owners should each sign. When signing as attorney, executor, administrator, corporate officer, trustee, guardian, or custodian, please give full title. Date (mm/dd/yyyy) — Please print date below. Signature 1 — Please keep signature within the box. Signature 2 — Please keep signature within the box. C 1234567890 J N T MR A SAMPLE (THIS AREA IS SET UP TO ACCOMMODATE 140 CHARACTERS) MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND MMMMMMM1PCF 620996 MR A SAMPLE AND MR A SAMPLE AND MR A SAMPLE AND + 040SSA

The 2024 Special Meeting of UMB Financial Corporation will be held on August 6, 2024 at 9:00 a.m. CDT, virtually via the internet at meetnow.global/MD9TFPP. To access the virtual meeting, you must have the information that is printed in the shaded bar located on the reverse side of this form. Small steps make an impact. Help the environment by consenting to receive electronic delivery, sign up at www.envisionreports.com/UMBF qIF VOTING BY MAIL, SIGN, DETACH AND RETURN THE BOTTOM PORTION IN THE ENCLOSED ENVELOPE. q Proxy — UMB Financial Corporation + THIS PROXY IS SOLICITED ON BEHALF OF THE BOARD OF DIRECTORS FOR THE SPECIAL MEETING ON AUGUST 6, 2024 The undersigned hereby appoints J. Mariner Kemper, James Rine and Ram Shankar or any of them, with full power of substitution as proxies, to represent and vote all shares of Common Stock of UMB Financial Corporation, which the undersigned is entitled to vote at the Special Meeting to be held on August 6, 2024, at 9:00 a.m., and any adjournment or postponement of the meeting. This proxy revokes all prior proxies given by the undersigned. Management knows of no other matters to be brought before the Special Meeting; however, the persons named as proxy holders or their substitutes will vote in their discretion with respect to any other matters that are properly brought before the Special Meeting or any adjournment or postponement of the meeting. This proxy, when properly executed, will be voted in the manner directed herein by the undersigned shareholder or absent instruction, will be voted FOR on Proposal 1, 2 and 3. In their discretion, the persons named as proxy holders or their substitutes are authorized to vote upon such other business as may properly come before the meeting. (Items to be voted appear on reverse side.) C Non-Voting Items Change of Address — Please print new address below. +