A clause in the Constitution stating that states in the United States must recognize the validity of judicial decisions and legislative acts originating within other states.
The full faith and credit clause, Article IV, section 1, of the Constitution, mandates that each state must give at least the same effect to the laws and court judgments of another state as would that other state. Although this clause covers “public acts” and “records” as well as judicial proceedings, it is most often applied to the recognition of court judgments from other states.
Not all state court judgments are entitled to full faith and credit. Every state that is asked to recognize another state’s court judgment must determine what effect, if any, the judgment would have in the state that rendered it. Generally, if that judgment is not a final judgment on the merits, it is not entitled to full faith and credit. For example, a judgment based on a procedural error is not a “judgment on the merits.” Likewise, a judgment rendered by a state court that lacked jurisdiction over the subject matter of the lawsuit or over the parties to the lawsuit is not entitled to full faith and credit in another state. To be a final judgment on the merits, a court judgment must have been entered by a state court that had the power to hear the particular dispute and based on the substantive law applicable to the dispute. After determining the effect and validity of a particular state court judgment in the state that rendered it, then the other state must give the same force and effect to that court judgment.
The application of the full faith and credit clause can lead to peculiar results. In Fauntleroy v. Lum
Finality of decision
States’ rights and state sovereignty