WHITE MOUNTAINS INSURANCE GROUP LTD

The Principal Executive Officer (“PEO”) and the Principal Financial Officer (“PFO”) of White Mountains have evaluated the effectiveness of its disclosure controls and procedures (as defined in Rule 13a-15(e) of the Exchange Act) as of December 31, 2023. Based on that evaluation, the PEO and PFO have concluded that White Mountains’s disclosure controls and procedures are adequate and effective.

The PEO and the PFO of White Mountains have evaluated the effectiveness of its internal control over financial reporting as of December 31, 2023. Based on that evaluation, the PEO and PFO have concluded that White Mountains’s internal control over financial reporting is effective. Management’s annual report on internal control over financial reporting is included on page F-73 of this report. The attestation report on the effectiveness of our internal control over financial reporting by PricewaterhouseCoopers LLP is included on page F-74 of this report.

There has been no change in White Mountains’s internal controls over financial reporting that occurred during the fourth quarter of 2023 that has materially affected, or is reasonably likely to materially affect, White Mountains’s internal control over financial reporting.