Corporate Headquarters:
White Mountains Insurance Group, Ltd.
A.S. Cooper Building, 26 Reid Street
Hamilton HM 11
Bermuda
Tel: 441-278-3160
Fax: 441-278-3170

Mailing Address:
White Mountains Insurance Group, Ltd.
P.O. Box HM 668
Hamilton HM CX
Bermuda

Registered Office (location of shareholder records):
White Mountains Insurance Group, Ltd.
Clarendon House
2 Church Street
Hamilton HM 11
Bermuda

Principal Executive Office:
White Mountains Insurance Group, Ltd.
23 South Main Street, Suite 3B
Hanover, New Hampshire 03755
Tel: 603-640-2200
Fax: 603-640-2250

Investor Inquiries:
White Mountains Insurance Group, Ltd.
23 South Main Street, Suite 3B
Hanover, New Hampshire 03755
Attn: Investor Relations
Tel: 603-640-2212
Fax: 603-640-2250
Email: ir@whitemountains.com

Shareholder Inquiries:
White Mountains Insurance Group, Ltd.
23 South Main Street, Suite 3B
Hanover, New Hampshire 03755
Attn: Corporate Secretary
Tel: 603-640-2200
Fax: 603-640-2250
E-mail: info@whitemountains.com

Transfer Agent and Registrar for Common Shares:
Mailing Address:
Computershare Trust Company, N.A. www.computershare.com
PO Box 43006
Providence, RI 02940-3006

Private Couriers/Registered Mail:
Computershare Trust Company, N.A.
150 Royall St, Suite 101
Canton, MA 02021

Telephone Response Center:
Tel: 877-373-6374
Hearing Impaired; TDD: (800) 952-9245

Independent Auditors:
PricewaterhouseCoopers
101 Seaport Boulevard, Suite 500
Boston, MA 02210

Tel: 617-530-5000