Who is referred to as the person who purchases the annuity plan?

The term that refers to the individual who purchases the annuity plan is the "Owner." The owner is the person who enters into the contract with the insurance company and pays the premiums or contributions toward the annuity. While the annuitant is the individual on whose life the annuity payments are based, and they may or may not be the same as the owner, the distinction is important.

The owner retains control over the annuity, including decisions such as the payment options and the ability to change beneficiaries. In many cases, the annuitant is simply the individual whose life expectancy determines when and how much the payouts occur, but they do not necessarily have to be the person who purchased the annuity.

Now, regarding the other terms: the assignor refers to someone who transfers their rights under the contract to another party, and the insured is typically applicable in life insurance contracts, not annuities. Thus, “Owner” is indeed the accurate term for the person who purchases the annuity plan.