SO: Other company developments

Item 8.01. Other Events . On August 3, 2026, The Southern Company (the “Company”) issued a press release announcing proposed offerings of $650 million aggregate principal amount of convertible senior notes due 2027 (the “2027 Convertible Notes”) and $1.5 billion aggregate principal amount of convertible senior notes due 2029 (the “2029 Convertible Notes” and, together with the 2027 Convertible Notes, the “Convertible Notes”) in private offerings to persons reasonably believed to be qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended. In addition, the Company expects to grant the initial purchasers options to purchase, for settlement within a period of 13 days from, and including, the date the Convertible Notes are first issued, up to an additional $97.5 million aggregate principal amount of the 2027 Convertible Notes and up to an additional $225 million aggregate principal amount of the 2029 Convertible Notes. A copy of the press release is attached hereto as Exhibit 99.1 and incorporated by reference herein. Item 9.01. Financial Statements and Exhibits . (d) Exhibits. 99.1 Press Release issued by the Company on August 3, 2026 announcing the proposed offerings of the Convertible Notes. 104 Cover Page Interactive Data File – The cover page iXBRL tags are embedded within the inline XBRL document. SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Date: August 3, 2026 THE SOUTHERN COMPANY By /s/Melissa K. Caen Melissa K. Caen Assistant Secretary 2