Vistra Corp.

An evaluation was performed under the supervision and with the participation of our management, including the principal executive officer and principal financial officer, of the effectiveness of the design and operation of the disclosure controls and procedures (as such term is defined in Rules 13a-15(e) and 15a-15(e) of the Exchange Act) in effect at June 30, 2025. Based on the evaluation performed, our principal executive officer and principal financial officer concluded that the disclosure controls and procedures were effective as of that date.

There have been no changes in our internal control over financial reporting (as such term is defined in Rules 13a-15(e) and 15a-15(e) of the Exchange Act) during the most recently completed fiscal quarter that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting. While there were no material changes to our internal control over financing reporting during the second quarter of 2025, we are currently in process of an ERP implementation which we expect to complete during the third quarter of 2025. As a result of the implementation, we expect certain changes to our processes and procedures, which, in turn, will result in changes to our internal control over financial reporting. While we expect this implementation to either strengthen or have minimal impact to our existing internal controls, we will continue to evaluate and monitor our internal control over financial reporting as processes and procedures are finalized with the implementation.