SO: 10-Q financial filing

so-20260930 Table of Contents Index to Financial Statements UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number Registrant, State of Incorporation, Address and Telephone Number I.R.S. Employer Identification No. 1-3526 The Southern Company 58-0690070 (A Delaware Corporation) 30 Ivan Allen Jr. Boulevard, N.W. Atlanta , Georgia 30308 ( 404 ) 506-5000 1-3164 Alabama Power Company 63-0004250 (An Alabama Corporation) 600 North 18th Street Birmingham , Alabama 35203 ( 205 ) 257-1000 1-6468 Georgia Power Company 58-0257110 (A Georgia Corporation) 241 Ralph McGill Boulevard, N.E. Atlanta , Georgia 30308 ( 404 ) 506-6526 001-11229 Mississippi Power Company 64-0205820 (A Mississippi Corporation) 2992 West Beach Boulevard Gulfport , Mississippi 39501 ( 228 ) 864-1211 001-37803 Southern Power Company 58-2598670 (A Delaware Corporation) 30 Ivan Allen Jr. Boulevard, N.W. Atlanta , Georgia 30308 ( 404 ) 506-5000 1-14174 Southern Company Gas 58-2210952 (A Georgia Corporation) 725 W. Peachtree Street, N.E. Atlanta , Georgia 30308 ( 404 ) 584-4000 Table of Contents Index to Financial Statements Securities registered pursuant to Section 12(b) of the Act: Registrant Title of Each Class Trading Symbol(s) Name of Each Exchange on Which Registered The Southern Company Common Stock, par value $0.01 per share SO New York Stock Exchange (NYSE) The Southern Company Series 2017B 5.25% Junior Subordinated Notes due 2077 SOJC NYSE The Southern Company Series 2020A 4.95% Junior Subordi