X0508 4 2024-02-03 0 0000092122 SOUTHERN CO SO 0001849295 Spainhour Sterling A Jr. 30 IVAN ALLEN JR BLVD NW ATLANTA GA 30308 0 1 0 0 EVP, Chief Legal Officer & CCO 0 Southern Company Common Stock 2024-02-03 4 M 0 552 0.00 A 9614 D Southern Company Common Stock 2024-02-03 4 F 0 279 68.65 D 9335 D Southern Company Common Stock 5335.5391 I 401K Southern Co Restricted Stock Units 0.00 2024-02-03 4 M 0 490 0.00 D Southern Company Common Stock 490 0 D Shares acquired upon vesting of final 1/3 of restricted stock units granted on February 3, 2021. Includes 62 accrued dividend equivalent units. Shares withheld to satisfy required state and federal tax withholding requirements. Represents final 1/3 of restricted stock units granted on February 3, 2021. Each restricted stock unit represents the right to receive, at settlement one share of common stock. Additional units will be acquired with deemed dividends. Shares will be withheld upon vesting to satisfy tax requirements. /s/ Myra C. Bierria, Attorney-in-Fact for Sterling A. Spainhour 2024-02-06