"Next of kin" is a term most commonly used in estate law and refers to the default individuals who inherit part of an estate when the deceased leaves no will.
Next of kin most often means the closest blood relatives to the deceased, which in most jurisdictions, includes the surviving spouse.
Determining/finding the decedent’s next of kin is an important step in estate law when an estate holder dies without leaving a will. Many jurisdictions statutorily require estates to be divided among the next of kin when a will is absent. This practice reflects the assumption that a deceased individual’s next of kin are the closest, most loved people in the deceased’s life, and that the deceased would naturally want the estate to go to these people.