X0508 4 2024-11-11 0000944695 HANOVER INSURANCE GROUP, INC. THG 0001269358 BARNES WARREN E. C/O THE HANOVER INSURANCE GROUP, INC. 440 LINCOLN STREET WORCESTER MA 01653 0 1 0 0 SVP & Princpl. Accntg. Officer 0 Common Stock 2024-11-11 4 M 0 1392 115.35 A 4416.319 D Common Stock 2024-11-11 4 S 0 1392 162.23 D 3024.319 D Common Stock Option (right to buy) 115.35 2024-11-11 4 M 0 1392 0 D 2031-02-26 Common Stock 1392 0 D The price reported in Column 4 is a weighted average price. The shares were sold at multiple prices ranging from $161.86 to $162.73. The Reporting Person undertakes to provide The Hanover Insurance Group, Inc. ("THG"), any security holder of THG, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range set forth above. The option, representing the right to purchase a total of 2,088 shares, vested 1/3 on each of February 26, 2022, February 26, 2023 and February 26, 2024. /s/ Lindsay L. Katz pursuant to Confirming Statement 2024-11-13