X0306 4 2023-02-11 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 Southern Company Common Stock 2023-02-11 4 M 0 2371 0.00 A 95401 D Southern Company Common Stock 2023-02-11 4 F 0 1052 66.88 D 94349 D Southern Company Common Stock 13554.8219 I By 401(k) Performance Restricted Stock Units 0.00 2023-02-11 4 M 0 2101 0.00 D Southern Company Common Stock 2101 0 D Shares acquired upon vesting of final 1/3 of performance restricted stock units granted on February 11, 2020. Includes 270 accrued dividend equivalent units. Shares withheld to satisfy required state and federal tax withholding requirements. Represents final 1/3 of performance restricted stock units granted on February 11, 2020. Each performance 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 Stan W. Connally 2023-02-14