Rule 635 An obligation possessed by the creditor is presumed not to have been paid.

If someone is owed money or some other debt, and they still have the original document proving that debt, the court will assume the debt has not been paid yet.

This means the person who owes the money would need to show proof of payment, like a receipt or bank record. Just saying "I paid it" is not enough to overcome this presumption. The burden falls on the person who claims they paid to back that up with evidence.