ART. 1277. Confusion does not extinguish a joint obligation except as regards the share corresponding to the creditor or debtor in whom the two characters concur. (1194)
In a join obligation, there are as many debts as there are debtors and credits as there are creditors. It is considered that these debts and credits are distinct and separate.[1][2] When confusion takes place in a joint obligation, the obligation is only extinguished in so far as the share in the debt and credit of the corresponding debtor and creditor in whom the two characters merged. As to the obligation of other joint debtors and creditors, it will remain the same.However, when confusion takes place in solidary obligation, the obligation is extinguished but the other debtors may be liable for reimbursement if payment was made prior to remission.[3][4]
[1] Article 1208, Civil Code.
[2] De Leon. (2014). Obligations and Contracts.
[3] Article 1215, Civil Code.
[4] Paragraph 2, Article 1217, Civil Code.