La. Civ. Code art. 1831 : Civil Code — OF THE DIFFERENT MODES OF ACQUIRING THE OWNERSHIP OF THINGS — OBLIGATIONS IN GENERAL — PROOF OF OBLIGATIONS — Party must prove obligation

A party who demands performance of an obligation must prove the existence of the obligation.

A party who asserts that an obligation is null, or that it has been modified or extinguished, must prove the facts or acts giving rise to the nullity, modification, or extinction.