X0206 3 2023-04-01 0 0000092122 SOUTHERN CO SO 0001849295 Spainhour Sterling A Jr. 30 IVAN ALLEN JR BLVD NW ATLANTA GA 30308 0 1 0 0 EVP, Chief Legal Officer & CCO Southern Company Common Stock 4772.0239 I 401K Southern Company Common Stock 9062 D Phantom Stock Units 0.00 Southern Company Common Stock 1236.6936 D Southern Co Restricted Stock Units 0.00 Southern Company Common Stock 1324 D Southern Co Restricted Stock Units 0.00 Southern Company Common Stock 490 D Acquired on various dates between January 6, 2017 to March 4, 2022 pursuant to Southern deferred compensation plan, at prices ranging from $42.89 to $67.58 per unit, payable in cash only upon termination. 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. Represents restricted stock units granted on February 3, 2021. The remaining award will vest 1/3 in 2024. Each restricted stock unit represents the right to receive, at settlement, one share of common stock. /s/Marcia R. DeMar, Attorney-in-Fact for Sterling A. Spainhour 2023-04-03