Step 1: Go to www.envisionreports.com/BFC Step 2: Click on Cast Your Vote or Request Materials. Step 3: Follow the instructions on the screen to log in. www.envisionreports.com/BFC Online Go to www.envisionreports.com/BFC or scan the QR code — login details are located in the shaded bar below. Annual Shareholder Meeting Notice 03YJTE + + Important Notice Regarding the Availability of Proxy Materials for the Bank First Corporation Shareholder Meeting to be Held on June 17, 2024. Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual shareholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. You may also vote via phone by calling the number listed in the above right corner of this notice. The items to be voted on and location of the Annual Meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The proxy statement and annual report to shareholders are available at: Obtaining a Paper Copy of the Proxy Materials – If you want to receive a paper copy of the proxy materials, you must request one. There is no charge to you for requesting a paper copy. Please make your request as instructed on the reverse side on or before June 7, 2024 to facilitate timely delivery. 2NOT Easy Online Access — View your proxy materials and vote. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. Votes submitted electronically must be received by 11:59 p.m. (CT) on June 16, 2024. MMMMMMMMMMMM MMMMMMMMM 1234 5678 9012 345 C 1234567890 COY MMMMMMM 000001MR A SAMPLE DESIGNATION (IF ANY) ADD 1 ADD 2 ADD 3 ADD 4 ADD 5 ADD 6 ENDORSEMENT_LINE______________ SACKPACK_____________ Phone Call toll free 1-800-652-VOTE (8683) within the USA, US territories and Canada

Here’s how to order a paper copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Online – Go to www.envisionreports.com/BFC. Click Cast Your Vote or Request Materials. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to investorvote@computershare.com with “Proxy Materials Bank First Corporation” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, all requests for a paper copy of proxy materials must be received by June 7, 2024. Bank First Corporation’s Annual Meeting of Shareholders will be held on Monday, June 17, 2024, at the Capitol Civic Centre, 913 South Eighth Street, Manitowoc, Wisconsin 54220, at 4:00pm CDT. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors recommends a vote FOR all nominees listed, FOR Proposals 2, 3 and 5, and for 3 YEARS on Proposal 4: 1. To elect five (5) directors of the Corporation, each for three-year terms and in each case until their successors are elected and qualified: 01 – Mary-Kay H. Bourbulas 02 – Erin A. Davis 03 – Robert D. Gregorski 04 – Phillip R. Maples 05 – Peter J. Van Sistine 2. To ratify the appointment of FORVIS, LLP as the Corporation’s independent registered public accounting firm for the fiscal year ending December 31, 2024. 3. To hold an advisory vote on the compensation of the Corporation’s named executive officers. 4. To hold an advisory vote on the frequency of the advisory vote on executive compensation. 5. To transact such other business as may properly come before the Annual Meeting or any adjournments or postponements thereof. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online, call, or request a paper copy of the proxy materials to receive a proxy card. If you wish to attend and vote at the meeting, please bring this notice with you. Annual Shareholder Meeting Notice

x		No fee required.

¨		Fee paid previously with preliminary materials:

¨		Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

Preliminary Proxy Statement

Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

Definitive Proxy Statement

Definitive Additional Materials

Soliciting Material Pursuant to § 240.14a-12