Q: Does the statute of limitations exempt debt among Jews?
A: In principle, halachah has no statute of limitations on debt; even if many years passed, it remains intact. Some places had a practice not to collect old debt from inheritors, or to more readily believe the borrower’s claim that it was paid (C.M. 98:1; Pischei Teshuvah 61:5).
Nonetheless, beis din must check carefully with long-past debt whether there is something suspicious; it would then refuse to deal with the case (C.M. 98:2; 61:9).
It is doubtful whether the concept of dina d’malchusa dina applies to the statute of limitations, but for debt in a commercial setting, the concept of minhag hamedinah (common commercial practice) would apply (Mishpetei Uziel, C.M. 4:28; Pischei Choshen, Halvaah 2:).