Can. 1620

A sentence suffers from the defect of irremediable nullity if: 1/ it was rendered by an absolutely incompetent judge; 2/ it was rendered by a person who lacks the power of judging in the tribunal in which the case was decided; 3/ a judge rendered a sentence coerced by force or grave fear; 4/ the trial took place without the judicial petition mentioned in can. 1501 or was not instituted against some respondent; 5/ it was rendered between parties, at least one of whom did not have standing in the trial; 6/ someone acted in the name of another without a legitimate mandate; 7/ the right of defense was denied to one or the other party; 8/ it did not decide the controversy even partially.