X0306 4 2022-10-04 0 0001667161 Randolph Bancorp, Inc. RNDB 0001429021 Parent William M C/O RANDOLPH BANCORP, INC. 2 BATTERYMARCH PARK, SUITE 301 QUINCY MA 02169 1 1 0 0 President and CEO Common Stock 2022-10-04 4 G 0 3391 26.95 D 18410 D Common Stock 2022-10-04 4 G 0 769 26.96 D 17641 D Common Stock 30964 I By IRA Common Stock 158 I ESOP Stock Option (Right to Buy) 11.48 2030-08-12 Common Stock 65000 65000 D Stock Option (Right to Buy) 8.78 2030-03-31 Common Stock 29412 29412 D Includes 6,000 shares of restricted stock which vest in annual installments of 2,000 shares from April 1, 2023, 7,500 shares of restricted stock which vest in annual installments of 2,500 shares from August 13, 2023 and 1,250 shares of restricted stock which vest in annual installments of 625 shares from August 13, 2023. Updated to reflect the most recent year's allocation of shares. The options vest in five equal annual installments beginning on August 13, 2021. The options vest in five equal annual installments beginning on April 1, 2021. /s/ William M. Parent 2022-10-05