California Code, Code of Civil Procedure - CCP § 999.3

(a) The recipients of a time-limited demand may accept the demand by providing written acceptance of the material terms outlined in Section 999.1 in their entirety.

(b) Upon receipt of a time-limited demand, an attempt to seek clarification or additional information or a request for an extension due to the need for further information or investigation, made during the time within which to accept a time-limited demand, shall not, in and of itself, be deemed a counteroffer or rejection of the demand.

(c) If, for any reason, an insurer does not accept a time-limited demand, the insurer shall notify the claimant, in writing, of its decision and the basis for its decision. This notification shall be sent prior to the expiration of the time-limited demand, including any extension agreed to by the parties, and shall be relevant in any lawsuit alleging extracontractual damages against the tortfeasor's liability insurer.