Life insurance or life assurance is a contract between the policy owner and the insurer, where the insurer agrees to pay a sum of money upon the occurrence of the insured individual's or individuals' death or other event, such as terminal illness or critical illness. In return, the policy owner agrees to pay a stipulated amount called a premium at regular intervals or in lump sums. There may be designs in some countries where bills and death expenses plus catering for after funeral expenses should be included in Policy Premium. In the United States, the predominant form simply specifies a lump sum to be paid on the insured's demise.

As with most insurance policies, life insurance is a contract between the insurer and the policy owner whereby a benefit is paid to the designated beneficiaries if an insured event occurs which is covered by the policy. To be a life policy the insured event must be based upon the lives of the people named in the policy.

Insured events that may be covered include:

• Serious illness

Life policies are legal contracts and the terms of the contract describe the limitations of the insured events. Specific exclusions are often written into the contract to limit the liability of the insurer; for example claims relating to suicide, fraud, war, riot and civil commotion.

Life-based contracts tend to fall into two major categories:

• Protection policies - designed to provide a benefit in the event of specified event, typically a lump sum payment. A common form of this design is term insurance.
• Investment policies - where the main objective is to facilitate the growth of capital by regular or single premiums. Common forms (in the US anyway) are whole life, universal life and variable life policies.

Parties to contract

There is a difference between the insured and the policy owner (policy holder), although the owner and the insured are often the same person. For example, if Joe buys a policy on his own life, he is both the owner and the insured. But if Jane, his wife, buys a policy on Joe's life, she is the owner and he is the insured. The policy owner is the guarantee and he or she will be the person who will pay for the policy. The insured is a participant in the contract, but not necessarily a party to it.

The beneficiary receives policy proceeds upon the insured's death. The owner designates the beneficiary, but the beneficiary is not a party to the policy. The owner can change the beneficiary unless the policy has an irrevocable beneficiary designation. With an irrevocable beneficiary, that beneficiary must agree to any beneficiary changes, policy assignments, or cash value borrowing.

In cases where the policy owner is not the insured (also referred to as the cestui qui vit or CQV), insurance companies have sought to limit policy purchases to those with an "insurable interest" in the CQV. For life insurance policies, close family members and business partners will usually be found to have an insurable interest. The "insurable interest" requirement usually demonstrates that the purchaser will actually suffer some kind of loss if the CQV dies. Such a requirement prevents people from benefiting from the purchase of purely speculative policies on people they expect to die. With no insurable interest requirement, the risk that a purchaser would murder the CQV for insurance proceeds would be great. In at least one case, an insurance company which sold a policy to a purchaser with no insurable interest (who later murdered the CQV for the proceeds), was found liable in court for contributing to the wrongful death of the victim (Liberty National Life v. Weldon, 267 Ala.171 (1957)).