Short answer. No. The Civil Code states plainly that unenforceable contracts cannot be assailed by third persons. Only the parties to the contract may raise its unenforceability. An outsider who was never part of the agreement has no standing to attack it on that ground.
What the law says
Unenforceable contracts cannot be assailed by third persons.
Civil Code, Article 1408 — Third Persons and Unenforceable Contracts. Read the full provision →
The defense belongs to the parties
Article 1408 is short but decisive: unenforceable contracts cannot be assailed by third persons. An unenforceable contract is one the law will not enforce through court action unless it is cured or ratified — for instance, certain agreements not put in the required written form, or those entered without proper authority. The point of this article is who may raise that defect. The answer is only the contracting parties. A stranger to the agreement cannot come forward and demand that the contract be treated as unenforceable, because the flaw exists for the protection of the parties, not for the benefit of outsiders.
Why outsiders are shut out
Unenforceability is a shield the parties may choose to raise or to waive. Because the law leaves it to them — they can ratify the contract and make it fully binding — the objection is personal to them. If any passerby could invoke it, a contract the parties themselves are content to honor could be undone by someone with no stake in it. The rule keeps control where it belongs. As between the parties, the contract stands unless one of them raises the defect; as against the world, its unenforceable character is simply not a weapon a third person may wield.
What the rule does not say
This provision addresses only the ground of unenforceability. It does not mean a contract can never affect or be questioned by anyone else on other, proper grounds — a person whose own rights are genuinely and directly prejudiced may have separate remedies the law provides in their own right. What Article 1408 forecloses is the specific move of a non-party trying to defeat a contract by labeling it unenforceable. The unenforceable nature of an agreement is a matter between those who made it, and outsiders cannot borrow that defect to serve their own purposes.
How this helps you
If someone who is a stranger to your contract is trying to attack it as unenforceable, Article 1408 stands squarely against them — that objection is not theirs to raise. Your agreement is not at the mercy of outsiders on that ground. If you are a party and the contract has an unenforceability problem, remember the defect is yours to raise or to cure through ratification, and acting on it consistently matters. Because whether a contract is truly unenforceable, and who counts as a party, can be technical questions, the specific facts deserve careful review.
Cases citing this provision
These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.
- Rapid City Realty and Development Corporation vs. Lourdes Estudillo Paez-Cline alias Lourdes Paez-Villa, et, G.R. No. 217148, December 7, 2021 — read the decision on LawPhil →