Usually, this is when the life insurance coverage has been approved by the insurance company and the first payment has been made to the insurance company or agent.
However, the claim will not be paid if the death is not covered by the policy, or did not occur while the life insurance policy was in effect.
Life insurance policies have certain exclusions for which coverage is not provided, such as, death as a result of war, or suicide within the first 1-2 years of owning the policy (depending on your state).