Basic rule on solidarity
The settled rule is that when there is no agreement as to solidarity, the
first and new debtors are considered to be jointly obligated.[1] This means
that each of the debtors is liable only for a proportionate part of the debt.
There is solidarity liability only when the obligation expressly so states,
when the law so provides or when the nature of the obligation so requires.[2]
This is because one who binds himself solidarity with the principal debtor
acts as a surety and essentially "undertakes directly for the payment and is
so responsible at once if the principal debtor makes default."[3]Under Article 1216 of the Civil Code, a creditor may proceed against any one
of the solidary debtors or some or all of them simultaneously. Article 1217
further provides that payment by one of the solidary debtors extinguishes the
obligation and he who made payment may claim from his co-debtors the share
which corresponds to each.[4]
[1] See Spouses Ibanez v. Harper, G.R. No. 194272, February 15, 2017.
[2] Carodan v. China Banking Corporation, G.R. No. 210542, February 24, 2016, 785 SCRA 179, 192.
[3] Id.
[4] See EscaƱo v. Ortigas, Jr., G.R. No. 151953, June 29, 2007, 526 SCRA 26.