EIGI Endurance International Group Holdings Inc

EXHIBIT 99.1 SIGNATURES OF REPORTING PERSONS After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this Form 4/A is true, complete and correct. February 9, 2015 WP EXPEDITION CO-INVEST L.P. By: Warburg Pincus Partners, L.P., its general partner By: Warburg Pincus Partners GP LLC, its general partner By: Warburg Pincus & Co., its managing member By: /s/ Robert B. Knauss ---------------------------------------------- Robert B. Knauss Partner WARBURG PINCUS PARTNERS, L.P. By: Warburg Pincus Partners GP LLC, its general partner By: Warburg Pincus & Co., its managing member By: /s/ Robert B. Knauss ---------------------------------------------- Robert B. Knauss Partner WARBURG PINCUS PARTNERS GP LLC By: Warburg Pincus & Co., its managing member By: /s/ Robert B. Knauss ---------------------------------------------- Robert B. Knauss Partner WARBURG PINCUS & CO. By: /s/ Robert B. Knauss ---------------------------------------------- Robert B. Knauss Partner CHARLES R. KAYE By: /s/ Robert B. Knauss ---------------------------------------------- Robert B. Knauss, Attorney-in-Fact* JOSEPH P. LANDY By: /s/ Robert B. Knauss ----------------------------------------------- Robert B. Knauss, Attorney-in-Fact* *The Power of Attorney given by each of Mr. Kaye and Mr. Landy was previously filed with the U.S. Securities & Exchange Commission on November 26, 2013 as an exhibit to a statement on Form 4 filed by Warburg Pincus Private Equity IX, L.P. with respect to Laredo Petroleum Holdings, Inc. (now known as Laredo Petroleum, Inc.) and is hereby incorporated by reference.