While an insured cannot expand the scope of an existing insurance policy’s coverage by waiver or estoppel, a would-be insured can rely on waiver or estoppel to show that the insurer agreed to provide the insurance despite the insured’s failure to perform a condition precedent to issuance of the policy, such as submission of medical forms or, in this case, being actively at work on the date the coverage was to begin. Here, the pre-enrollment forms for an employer’s life insurance employee benefit did not clearly inform the employee what was required for her to be in “active service” as required for the policy to take effect. The employee enrolled, and the employer deducted premiums from her pay for a year for the insurance benefit without any objection by the insurer. Held, the employer acted as an agent for the insurer with respect to the life insurance benefit and so its acts of deducting premiums counted as the insurer’s for purposes of waiver or estoppel to assert the “active service” precondition to coverage. See Elfstrom v. New York Life Ins. Co. (1967) 67 Cal.2d 503. The employee alleged facts sufficient to state a claim for insurance benefits based on waiver or estoppel as against the insurer, but not as against the employer which did not purport to offer insurance itself, and which as a government entity could not be bound by estoppel except under unusual circumstances not present here.