SOUTHERN CO

Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant. On August 6, 2026, The Southern Company (the “Company”) issued $833,750,000 aggregate principal amount of its Series 2026A 2.125% Convertible Senior Notes due December 15, 2027 (the “Series 2026A Convertible Senior Notes”) and $1,897,500,000 aggregate principal amount of its Series 2026B 3.50% Convertible Senior Notes due September 15, 2029 (the “Series 2026B Convertible Senior Notes” and, together with the Series 2026A Convertible Senior Notes, the “Convertible Notes”) pursuant to the Senior Note Indenture (the “Senior Note Indenture”) dated as of June 1, 2026, as supplemented and amended by a First Supplemental Indenture (the “First Supplemental Indenture”) related to the Series 2026A Convertible Senior Notes and a Second Supplemental Indenture (the “Second Supplemental Indenture” and, together with the First Supplemental Indenture, the “Supplemental Indentures”) related to the Series 2026B Convertible Senior Notes, each dated as of August 6, 2026 (the Senior Note Indenture, as so supplemented and amended by the applicable Supplemental Indenture, the “Indenture”), between the Company and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”). Each series of Convertible Notes was sold under a Purchase Agreement (each, a “Purchase Agreement”) dated August 3, 2026 among the Company and the initial purchasers (the “Initial Purchasers”) party thereto. The $833,750,000 aggregate principal amount of Series 2026A Convertible Senior Notes and $1,897,500,000 aggregate principal amount of Series 2026B Convertible Senior Notes issued included $108,750,000 aggregate principal amount of Series 2026A Convertible Senior Notes and $247,500,000 aggregate principal amount of Series 2026B Convertible Senior Notes issued upon the exercise by the Initial Purchasers of their over-allotment options. Series 2026A Convertible Senior Notes Interest on the Series 2026A Convertible Senior Notes is payable semiannually in arrears on the 15th day of June and December of each year, beginning December 15, 2026. The Series 2026A Convertible Senior Notes will mature on December 15, 2027, unless earlier converted or repurchased. The Series 2026A Convertible Senior Notes are direct, unsecured and unsubordinated obligations of the Company, ranking equally with all of the Company’s other unsecured and unsubordinated indebtedness from time to time outstanding and are effectively subordinated to all secured indebtedness of the Company. The Series 2026A Convertible Senior Notes are not redeemable at the option of the Company. Holders may convert their Series 2026A Convertible Senior Notes at their option prior to the close of business on the business day preceding September 15, 2027, but only under the following circumstances: • during any calendar quarter commencing after the calendar quarter ending on September 30, 2026 (and only during such calendar quarter), if the last reported sale price of the Company’s Common Stock, par value $0.01 per share (the “Common Stock”), for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day as determined by the Company; • during the five business day period after any 10 consecutive trading day period (the “Measurement Period”) in which the trading price per $1,000 principal amount of Series 2026A Convertible Senior Notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price of the Common Stock and the conversion rate on each such trading day; or • upon the occurrence of specified corporate events. On or after September 15, 2027, a holder may convert all or any portion of its Series 2026A Convertible Senior Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date regardless of the foregoing conditions. The conversion rate initially equals 9.5641 shares of Common Stock per $1,000 principal amount of Series 2026A Convertible Senior Notes (equivalent to an initial conversion price of approximately $104.56 per share of Common Stock). The conversion rate will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a Make-Whole Fundamental Change (as defined in the First Supplemental Indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares of Common Stock for a holder that elects to convert its Series 2026A Convertible Senior Notes in connection with such Make-Whole Fundamental Change. The Company will settle conversions of the Series 2026A Convertible Senior Notes by paying cash up to the aggregate principal amount of the Series 2026A Convertible Senior Notes to be converted and paying or delivering, as the case may be, cash, shares of Common Stock or a combination of cash and shares of Common Stock, at the Company’s election, in respect of the remainder, if any, of the Company’s conversion obligation in excess of the aggregate principal amount of the Series 2026A Convertible Senior Notes being converted. Upon the occurrence of a Fundamental Change (as defined in the First Supplemental Indenture), other than an Excluded Fundamental Change (as defined in the First Supplemental Indenture), holders may require the Company to purchase all or a portion of their Series 2026A Convertible Senior Notes, in principal amounts equal to $1,000 or an integral multiple thereof, for cash at a price equal to 100% of the principal amount of the Series 2026A Convertible Senior Notes to be purchased plus any accrued and unpaid interest. If an Event of Default (as defined in the Indenture) occurs and is continuing with respect to the Series 2026A Convertible Senior Notes, then the Trustee or the holders of not less than 25% in aggregate outstanding principal amount of the Series 2026A Convertible Senior Notes may declare the principal amount of the Series 2026A Convertible Senior Notes due and payable immediately. Series 2026B Convertible Senior Notes Interest on the Series 2026B Convertible Senior Notes is payable semiannually in arrears on the 15th day of March and September of each year, beginning March 15, 2027. The Series 2026B Convertible Senior Notes will mature on September 15, 2029, unless earlier converted or repurchased. The Series 2026B Convertible Senior Notes are direct, unsecured and unsubordinated obligations of the Company, ranking equally with all of the Company’s other unsecured and unsubordinated indebtedness from time to time outstanding and are effectively subordinated to all secured indebtedness of the Company. The Series 2026B Convertible Senior Notes are not redeemable at the option of the Company. Holders may convert their Series 2026B Convertible Senior Notes at their option prior to the close of business on the business day preceding June 15, 2029, but only under the following circumstances: • during any calendar quarter commencing after the calendar quarter ending on September 30, 2026 (and only during such calendar quarter), if the last reported sale price of the Common Stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day as determined by the Company; • during the five business day period after any Measurement Period in which the trading price per $1,000 principal amount of Series 2026B Convertible Senior Notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price of the Common Stock and the conversion rate on each such trading day; or • upon the occurrence of specified corporate events. On or after June 15, 2029, a holder may convert all or any portion of its Series 2026B Convertible Senior Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date regardless of the foregoing conditions. The conversion rate initially equals 8.4389 shares of Common Stock per $1,000 principal amount of Series 2026B Convertible Senior Notes (equivalent to an initial conversion price of approximately $118.50 per share of Common Stock). The conversion rate will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a Make-Whole Fundamental Change (as defined in the Second Supplemental Indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares of Common Stock for a holder that elects to convert its Series 2026B Convertible Senior Notes in connection with such Make-Whole Fundamental Change. The Company will settle conversions of the Series 2026B Convertible Senior Notes by paying cash up to the aggregate principal amount of the Series 2026B Convertible Senior Notes to be converted and paying or delivering, as the case may be, cash, shares of Common Stock or a combination of cash and shares of Common Stock, at the Company’s election, in respect of the remainder, if any, of the Company’s conversion obligation in excess of the aggregate principal amount of the Series 2026B Convertible Senior Notes being converted. Upon the occurrence of a Fundamental Change (as defined in the Second Supplemental Indenture), other than an Excluded Fundamental Change (as defined in the Second Supplemental Indenture), holders may require the Company to purchase all or a portion of their Series 2026B Convertible Senior Notes, in principal amounts equal to $1,000 or an integral multiple thereof, for cash at a price equal to 100% of the principal amount of the Series 2026B Convertible Senior Notes to be purchased plus any accrued and unpaid interest. If an Event of Default (as defined in the Indenture) occurs and is continuing with respect to the Series 2026B Convertible Senior Notes, then the Trustee or the holders of not less than 25% in aggregate outstanding principal amount of the Series 2026B Convertible Senior Notes may declare the principal amount of the Series 2026B Convertible Senior Notes due and payable immediately. Additional Information The foregoing descriptions of the Convertible Senior Notes and the Indenture do not purport to be complete and are qualified in their entirety by reference to the complete text of the Senior Note Indenture, the Supplemental Indentures and the forms of Convertible Senior Notes, which are filed as exhibits to this Current Report on Form 8-K and incorporated herein by reference.

Item 3.02. Unregistered Sales of Equity Securities. The information set forth under Item 2.03 is incorporated into this Item 3.02 by reference. The Company offered and sold the Convertible Notes to the Initial Purchasers in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), and for resale by the Initial Purchasers to persons reasonably believed to be qualified institutional buyers pursuant to the exemption from registration provided by Rule 144A under the Securities Act. The Company relied on these exemptions from registration based in part on representations made by the Initial Purchasers in each Purchase Agreement. The shares of Common Stock issuable upon conversion of the Convertible Notes, if any, have not been registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. The Company expects any shares of Common Stock issued upon conversion of the Convertible Notes to be issued pursuant to the exemption provided by Section 3(a)(9) of the Securities Act. Initially, (i) a maximum of 8,970,816 shares of Common Stock may be issued upon conversion of the Series 2026A Convertible Senior Notes and (ii) a maximum of 20,416,341 shares of Common Stock may be issued upon conversion of the Series 2026B Convertible Senior Notes, in each case based on the initial maximum conversion rate of 10.7596 shares of Common Stock per $1,000 principal amount of Convertible Notes and subject to anti-dilution adjustments.