Bonuses are declared at the end of the financial year. But, what if a policy matures or death occurs before the end of that period? Insurers declare interim bonus to take care of such situations and to avoid putting such policyholders at a disadvantage. The amount of bonus, however, is added to the policy on pro-rata basis for that specific year.
A money back life insurance policy is basically a type of an endowment life insurance policy. In an endowment life insurance policy you get the maturity benefits (sum assured + bonus) only at the end of the tenure of the life insurance policy. The money back life insurance policy pays you money at certain fixed time intervals across the tenure of the policy.