Reimbursement for payment made by third person

The rule in payments made by a third person is governed by Article 1236, to wit:
ART. 1236. The creditor is not bound to accept payment or performance by a third person who has no interest in the fulfillment of the obligation, unless there is a stipulation to the contrary.

Whoever pays for another may demand from the debtor what he has paid, except that if he paid without the knowledge or against the will of the debtor, he can recover only insofar as the payment has been beneficial to the debtor. (1158a)
The creditor is not bound to accept payment or performance by a third person who has no interest in the fulfillment of the obligation. The creditor may refuse payment by a third person. If the third person already payed, s/he can reimburse the payment. If the third person pays with debtor's consent, s/he may claim reimbursement for the full amount.[1] Also, the third person is presumed to be legally subrogated.[2] However, if the third person pays without the consent or knowledge of the debtor, the third party may only claim insofar as the payment has been beneficial to the debtor.[3] Furthermore, the third party cannot compel the creditor to subrogate him on his rights.[4]

[1] Article 1236, Civil Code.

[2] Article 1302, Civil Code.

[3] Second paragraph, Article 1236, Civil Code.

[4] Article 1237, Civil Code.