X0508 4 2024-02-07 0 0000092122 SOUTHERN CO SO 0001498337 Connally Stan W 30 IVAN ALLEN JR. BLVD ATLANTA GA 30308 0 1 0 0 Executive Vice President, SCS 0 Southern Company Common Stock 2024-02-07 4 A 0 41433 0.00 A 156099 D Southern Company Common Stock 2024-02-07 4 F 0 18377 66.95 D 137722 D Southern Company Common Stock 2024-02-07 4 M 0 2462 0.00 A 140184 D Southern Company Common Stock 2024-02-07 4 F 0 1093 66.95 D 139091 D Southern Company Common Stock 14230.642 I By 401(k) Performance Restricted Stock Units 0.00 2024-02-07 4 M 0 2364 0.00 D Southern Company Common Stock 2364 4727 D Shares acquired upon vesting of performance share units under Company's Performance Share Program for the 2021-2023 award. The Compensation and Talent Development Committee certified performance on February 7, 2024. 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 performance restricted stock units granted on February 1, 2023. The Compensation and Talent Development Committee certified performance on February 7, 2024. Includes 98 accrued dividend equivalent units. Represents first 1/3 of performance 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 Stan W. Connally 2024-02-08