PROXY ALARM.COM HOLDINGS, INC. Important Notice Regarding the Availability of Proxy Materials for the Annual Meeting of Stockholders to be held virtually on June 9, 2021 This communication is not a form of voting and 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 Notice and Proxy Statement and Annual Report to Stockholders are available at www.viewproxy.com/ALRM/2021. If you want to receive a paper or e-mail copy of these documents, you must request one. There is no charge to you for requesting a copy. Please make your request for a copy as instructed below on or before June 2, 2021 to facilitate timely delivery. Important information regarding the Internet availability of the Company’s proxy materials, instructions for accessing your proxy materials and voting online and instructions for requesting paper or e-mail copies of your proxy materials are provided on the reverse side of this Notice. The 2021 Annual Meeting of Stockholders of Alarm.com Holdings, Inc. will be held virtually on June 9, 2021 at 9:00 A.M. EDT. As a Registered Holder, you may attend the Annual Meeting via the Internet and vote your shares during the Annual Meeting by first registering at http://www.viewproxy. com/ALRM/2021 using your Virtual Control Number below. Your registration must be received by 11:59 p.m. EDT on June 7, 2021. On the day of the Annual Meeting of Stockholders, if you have properly registered, you may enter the meeting by clicking on the link received via email in your registration confirmation. Please have your Virtual Control Number with you during the Annual Meeting in order to vote. Further instructions on how to attend and vote during the Annual Meeting are contained in the Proxy Statement in the sections titled “Questions and Answers About These Proxy Materials and Voting - How do I attend the Annual Meeting?” and “Questions and Answers About These Proxy Materials and Voting - How can I vote?” (1) To elect the two (2) nominees for director named below to hold office until the 2024 Annual Meeting of Stockholders; Nominees: 01 Darius G. Nevin 02 Stephen Trundle (2) To ratify the selection by the Audit Committee of the Board of Directors of PricewaterhouseCoopers LLP as the independent registered public accounting firm of the Company for its fiscal year ending December 31, 2021. (3) To approve, on an advisory basis, the compensation of the Company’s named executive officers as disclosed in the accompanying Proxy Statement. (4) To consider, if properly presented at the Annual Meeting, a non-binding stockholder proposal requesting the Board of Directors to take each step necessary to amend the Company’s Amended and Restated Certificate of Incorporation and/or Amended and Restated Bylaws to eliminate the plurality voting standard for the election of directors. (5) To amend the Company’s Amended and Restated Certificate of Incorporation to reorganize the Board of Directors into one class, with each director subject to election each year for a one-year term. Note: To conduct any other business properly brought before the Annual Meeting or any adjournment thereof. The Board of Directors recommends a vote “FOR” each of the director nominees listed in Proposal 1, “FOR” Proposals 2, 3 and 5, and “AGAINST” Proposal 4. The Securities and Exchange Commission rules permit us to make our proxy materials available to our stockholders via the Internet. Material for this Annual Meeting and future meetings may be requested by one of the following methods: Go to www.viewproxy.com/ALRM/2021. Have the 11-digit control number available when you access the website and follow the instructions. 877-777-2857 TOLL FREE requests@viewproxy.com * If requesting material by e-mail, please send a blank e-mail with “ALRM” and your 11-digit control number (located below) in the subject line. No other requests, instructions or other inquiries should be included with your e-mail requesting material. You must use the 11-digit control number located in the box below to attend the Annual Meeting virtually, to vote via Internet or to request proxy materials. CONTROL NO. INTERNET TELEPHONE E-MAIL

ALARM.COM HOLDINGS, INC. HOW TO REGISTER FOR THE VIRTUAL ANNUAL MEETING The 2021 Annual Meeting of Stockholders of Alarm.com Holdings, Inc. will be held virtually on June 9, 2021 at 9:00 A.M. EDT. As a Registered Holder, you may attend the Annual Meeting via the Internet and vote your shares during the Annual Meeting by first registering at http://www.viewproxy.com/ALRM/2021 using your Virtual Control Number. Your registration must be received by 11:59 p.m. EDT on June 7, 2021. On the day of the Annual Meeting of Stockholders, if you have properly registered, you may enter the meeting by clicking on the link received via email in your registration confirmation. Please have your Virtual Control Number with you during the Annual Meeting in order to vote. Further instructions on how to attend and vote during the Annual Meeting are contained in the Proxy Statement in the sections titled “Questions and Answers About These Proxy Materials and Voting - How do I attend the Annual Meeting?” and “Questions and Answers About These Proxy Materials and Voting - How can I vote?” PROXY MATERIALS AVAILABLE TO VIEW OR RECEIVE The following proxy materials are available to you to review: • The Company’s Annual Report on Form 10-K • The Company’s 2021 Proxy Statement HOW TO ACCESS YOUR PROXY MATERIALS View Online: Have your 11-digit control number in hand and visit http://www.viewproxy.com/ALRM/2021 Request and Receive a Paper or E-Mail Copy: By Internet: http://www.viewproxy.com/ALRM/2021 By Telephone: 1-877-777-2857 TOLL FREE By E-Mail: requests@viewproxy.com. Please include “ALRM” and your 11-digit control number in the subject line; do not include any other text or message in the e-mail. VOTING METHODS Via Internet Prior to the Annual Meeting: Go to http://www.FCRVote.com/ALRM. Have your 11-digit control number available and follow the prompts. Your electronic vote prior to the Annual Meeting authorizes the named proxies to vote your shares in the same manner as if you marked, signed, dated and returned a proxy card. Via Internet During the Annual Meeting: Have your 11-digit control number available and follow the prompts. Via Mail: Request a paper copy of the materials which includes a proxy card. Follow the instructions on the proxy card for voting by mail. Via Telephone: Request a paper copy of the materials, which includes a proxy card. Follow the instructions on the proxy card for voting by telephone.

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