CW COSTCO WHOLESALE INCORPORATED UNDER THE LAWS SEE REVERSE FOR CERTAIN DEFINITIONS OF THE STATE OF WASHINGTON CUSIP 22160K 10 5 This Certifies that *******SPECIMEN******* is the record holder of FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, $.01 PAR VALUE, OF COSTCO WHOLESALE CORPORATION transferable on the books of the Corporation by the holder hereof in person or by duly authorized attorney upon surrender of this certificate properly endorsed. This certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar. WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers. Dated: /s/ [ILLEGIBLE] /s/ [ILLEGIBLE] SECRETARY [SEAL] PRESIDENT AND CHIEF EXECUTIVE OFFICER COUNTERSIGNED AND REGISTERED CHASEMELLON SHAREHOLDER SERVICES, L.L.C. TRANSFER AGENT AND REGISTRAR BY AUTHORIZED SIGNATURE