UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934 (Amendment No.)

Filed by the Registrant ☑ Filed by a Party other than the Registrant ¨

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¨	Preliminary Proxy Statement
¨	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
¨	Definitive Proxy Statement
þ	Definitive Additional Materials
¨	Soliciting Material Pursuant to §240.14a-12
Sundance Energy Inc.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
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¨	Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.
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+ Online Go to www.investorvote.com/SNDE or scan the QR code — login details are located in the shaded bar below. Important Notice Regarding the Availability of Proxy Materials for the Sundance Energy Inc. Annual Meeting of Stockholders to be Held on Wednesday, July 22, 2020. Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on at 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 2019 Annual Report on Form 10-k are available at: www.investorvote.com/SNDE Easy Online Access — View your proxy materials and vote. Step 1: Step 2: Step 3: Step 4: Step 5: Go to www.investorvote.com/SNDE. Click on the icon on the right to view meeting materials. Return to the investorvote.com window and follow the instructions on the screen to log in. Make your selections as instructed on each screen for your delivery preferences. Vote your shares. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before July 8, 2020 to facilitate timely delivery. + 2 N O T 039TNC Stockholder Meeting Notice

Sundance Energy Inc. Annual Meeting of Stockholders will be held on Wednesday, July 22, 2020 at 10:00 a.m. Mountain Time, virtually via the Internet at www.meetingcenter.io/201010988. To access the virtual meeting, you must have the 15-digit number that is printed in the shaded bar located on the reverse side of this form. The passcode for this meeting is: SNDE2020. Proposals to be voted on at the meeting are listed below along with the Board of Directors' recommendations. The Board of Directors recommend a vote FOR all the nominees listed and FOR Proposals 2 - 3: 1. Election of Directors: 01 - Stephen J. McDaniel 02 - Eric P. McCrady 03 - Judith D. Buie 04 - Damien A. Hannes 05 - H. Weldon Holcombe 06 - Neville W. Martin 07 - Thomas L. Mitchell Proposal to approve the Sundance Energy Inc. 2020 Equity Incentive Plan. Ratification of Deloitte & Touche LLP as the Company's independent registered public accounting firm for the year ending December 31, 2020. 2. 3. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online or request a paper copy of the proxy materials to receive a proxy card. Here’s how to order a 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. — — — Internet – Go to www.investorvote.com/SNDE. Phone – Call us free of charge at 1-866-641-4276. Email – Send an email to investorvote@computershare.com with “Proxy Materials Sundance Energy Inc.” 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, requests for a paper copy of proxy materials must be received by July 8, 2020. Stockholder Meeting Notice