1655. Subrogation may not be made by a debtor in favour of anyone except his lender and it takes effect without the consent of the creditor.
In order for subrogation to be valid in this case, the loan instrument and the acquittance shall each be made in the form of a notarial act en minute or by a private writing drawn up before two witnesses who sign it. In addition, a statement shall be made in the loan instrument that the loan is granted for the purpose of paying the debt, and, in the acquittance, that the debt is paid out of the loan.