SOUTHERN CO

The following table reports information regarding theadoption of "Rule 10b5-1 trading arrangements" or "non-Rule 10b5-1 trading arrangements," as defined in Item 408(a) of Regulation S-K, during the three months ended March 31, 2024 for Southern Company's directors and "officers," as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934, as amended. There were no modifications or terminations of such trading arrangements during the three months ended March 31, 2024. Unless otherwise indicated, each trading arrangement listed below is a "Rule 10b5-1 trading arrangement," provides for the sale of shares of Southern Company’s common stock, commences no earlier than the 120 th day after the "Date of Adoption" listed below, and terminates upon the earlier of the "Expiration Date" listed below or the completion of all sales. The Subsidiary Registrants had no reportable trading arrangements for the three months ended March 31, 2024.

(1)Includes shares underlying equity awards subject to accrual of dividend-equivalent rights. Accordingly, the total number of shares ultimately available for sale could be more than the amount shown. The amount shown is based on the dividend-equivalent rights accrued as of the date of adoption.