X0508 4 2024-02-01 0 0000092122 SOUTHERN CO SO 0001616250 Poroch David P. 30 IVAN ALLEN JR BLVD NW ATLANTA GA 30308 0 1 0 0 Comptroller 0 Southern Company Common Stock 2024-02-01 4 M 0 684 0.00 A 29375 D Southern Company Common Stock 2024-02-01 4 F 0 207 70.50 D 29168 D Southern Company Common Stock 4619.7792 I 401K Southern Co Restricted Stock Units 0.00 2024-02-01 4 M 0 656 0.00 D Southern Company Common Stock 656 1310 D Shares acquired upon vesting of first 1/3 of restricted stock units granted on February 1, 2023. Includes 28 accrued dividend equivalent units. Shares withheld to satisfy required state and federal tax withholding requirements. Represents first 1/3 of restricted stock units granted on February 1, 2023. The remaining award will vest 1/3 in 2025 and 1/3 in 2026. 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 David P. Poroch 2024-02-02