Extinguished by payment or performance, loss of thing due (by fortuitous event), and remission of debts
Payment
Includes money and performance (to do, and not to do)
Integrity of Prestation
The obligation must be performed completely
Identity of Prestation - The requirement to fulfill the obligation
Debts are not understood unless it has been delivered completely
Obligations that have been performed partially yet in good faith, the debtor may recover as if there has been a strict and complete fulfillment
If the creditor accepts the performance knowing it is irregular and complete, the obligation shall be deemed to be complied with
Creditor
Not intended to accept payment by third person who has no interest in fulfilling the obligation, unless there is a stipulation
Subrogation
When the third person acquires all the rights of the creditor; "Third person steps into the shoes of the creditor"
Reimbursement
Refund to the extent provided
Payment by third person to the obligation without knowledge of the debtor, the third person may recover the payment from the debtor only insofar as it has been beneficial to the latter, and there is no Subrogation
Payment by third person to the obligation with the knowledge and consent of the debtor, there is a Subrogation and Reimbursement
Any payer to the obligation without the consent of the debtor should not compel the creditor to subrogate
Any payment made by third person who has no intention of being reimbursed is deemed to be a Donation, although in some cases, the third person may recover to the extent
Payment shall be valid if the creditor accepts it
Any payment made by one who does not have free disposal of thing due and capacity to alienate is not valid, and therefore, it can be recovered