C.R.S. § 7-106-207

(1) Unless otherwise provided by the bylaws, the board of directors may authorize the issuance by the corporation of some or all of the shares of any or all of its classes or series without certificates. The authorization does not affect shares already represented by certificates until they are surrendered to the corporation. (2) Within a reasonable time after the issuance or transfer of shares without certificates, the corporation shall send to the shareholder a written statement of the information required on certificates by subsections (2) and (4) of section 7-106-206 and section 7-106-208 .