X0306 4 2023-02-13 0 0000092122 SOUTHERN CO SO 0001815666 Peoples James Jeffrey 30 IVAN ALLEN JR BLVD NW ATLANTA GA 30308 0 1 0 0 Chairman, President & CEO, APC Southern Company Common Stock 2023-02-13 4 A 0 9947 0.00 A 13315 D Southern Company Common Stock 2023-02-13 4 F 0 4412 67.13 D 8903 D Southern Company Common Stock 2023-02-13 4 M 0 787 0.00 A 9690 D Southern Company Common Stock 2023-02-13 4 F 0 348 67.13 D 9342 D Southern Company Common Stock 6645.5827 I 401K Southern Co Restricted Stock Units 0.00 2023-02-13 4 M 0 758 0.00 D Southern Company Common Stock 758 1516 D Shares acquired upon vesting of performance share units under Company's Performance Share Program for the 2020-2022 award. The Compensation and Management Succession Committee certified performance on February 13, 2023. Includes accrued dividend equivalent units. Shares withheld to satisfy required state and federal tax withholding requirements. Shares acquired upon vesting of first 1/3 of restricted stock units granted on February 13, 2022. Includes 29 accrued dividend equivalent units. Represents restricted stock units granted on February 13, 2022. The remaining award will vest 1/3 in 2024 and 1/3 in 2025. 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/ Marcia R. DeMar, Attorney-in-Fact for James J. Peoples 2023-02-15