IF the policy was an individual policy which was in force for over 2 years most companies pay it within 30 days from the time they receive the claim form with the death certificate.
If the policy was less than 2 years old (in which case materially false statements on the application could enable the company to void the policy), or there was an accident or strange circumstances involved (for example if the beneficiary might have been a murderer) then the company takes MUCH longer to investigate.
Many companies provide interest from date of death, or from a set point after filing also.