X0206 3 2021-09-01 0 0000092122 SOUTHERN CO SO 0001881495 Tucker Daniel S 30 IVAN ALLEN JR BLVD NW ATLANTA GA 30308 0 1 0 0 Executive Vice President & CFO Southern Company Common Stock 30449 D Southern Company Common Stock 3034.8258 I 401(K) Southern Company Common Stock 675.7477 I By Wife's 401(K) Phantom Stock Units 0.00 Southern Company Common Stock 3867.2084 D Southern Co Restricted Stock Units 0.00 Southern Company Common Stock 581 D Southern Co Restricted Stock Units 0.00 Southern Company Common Stock 831 D Southern Co Restricted Stock Units 0.00 Southern Company Common Stock 1506 D Southern Co. Performance Stock Units Holding 0.00 Southern Company Common Stock 4069 D Southern Co. Performance Stock Units Holding 0.00 Southern Company Common Stock 2910 D Southern Co. Performance Stock Units Holding 0.00 Southern Company Common Stock 3514 D Acquired on various dates between January 11, 2013 and August 27, 2021 pursuant to Southern deferred compensation plan, at prices ranging from $40.12 to $70.40 per unit, payable in cash only upon termination. Represents restricted stock units granted on February 11, 2019. The remaining 1/3 of the award will vest in 2022. Each restricted stock unit represents the right to receive, at statement, one share of common stock. Represents restricted stock units granted on February 11, 2020. The remaining award will vest 1/3 in 2022 and 1/3 in 2023. Each restricted stock unit represents the right to receive, at statement, one share of common stock. Restricted stock granted on February 3, 2021. The awards will vest one-third per year on the first, second and third anniversary of grant date. Each restricted stock unit represents the right to receive, at statement, one share of common stock. Performance share units granted on February 11, 2019. The award has a three year performance period and will vest on December 31, 2021. PSUs will convert to shares of Common Stock based on achievement of specific performance measures. Performance share units granted on February 11, 2020. The award has a three year performance period and will vest on December 31, 2022. PSUs will convert to shares of Common Stock based on achievement of specific performance measures. Performance share units granted on February 3, 2021. The award has a three year performance period and will vest on December 31, 2023. PSUs will convert to shares of Common Stock based on achievement of specific performance measures. /s/ Marcia R. DeMar, Attorney-in-Fact for Daniel S. Tucker 2021-09-13