Short answer. Yes, you may keep it. Article 1423 explains that natural obligations do not grant a right of action to enforce their performance, but after voluntary fulfillment by the obligor, they authorize the retention of what has been delivered or rendered. So because the payment was voluntary, the law lets you keep what you received.
What the law says
Natural obligations, not being based on positive law but on equity and natural law, do not grant a right of action to enforce their performance, but after voluntary fulfillment by the obligor, they authorize the retention of what has been delivered or rendered by reason thereof.
Civil Code, Article 1423 — Civil and Natural Obligations. Read the full provision →
What the law says
Civil obligations give a right of action to compel their performance.
Civil Code, Article 1423 — Civil and Natural Obligations. Read the full provision →
Civil versus natural obligations
Article 1423 divides obligations into two kinds. Civil obligations give a right of action to compel their performance — the creditor can sue and force payment. Natural obligations are different. They are not being based on positive law but on equity and natural law, and they do not grant a right of action to enforce their performance. This is why you could not have sued the payer: a natural obligation cannot be enforced in court. But the very same article draws the important consequence for the situation where the obligor pays anyway, which is exactly what happened to you.
Voluntary fulfilment lets you keep it
The article continues that natural obligations, after voluntary fulfillment by the obligor, they authorize the retention of what has been delivered or rendered by reason thereof. So although no court could have compelled payment, once the obligor freely paid, the law lets you keep it. The payment is not treated as a gift, nor as money paid by mistake that must be returned; it is the fulfilment of a real, if unenforceable, obligation grounded in equity. The payer cannot come back and demand a refund on the theory that he was never legally bound — his own voluntary act settled the matter.
Why 'voluntary' matters
The retention is authorised only where the fulfilment was voluntary. That word does the work. The payer must have paid freely — not under compulsion, and not through a genuine mistake about whether he was legally bound. Where a payment truly rests on a natural obligation and is made willingly, the law honours it and lets you retain it. But a payment squeezed out by force or intimidation, or made in the mistaken belief that a civil action still lay, does not carry the same protection, because it lacks the free choice the article demands. On your facts — a voluntary payment — the condition is met.
The limits of the rule
This article recognises the effect of natural obligations in general and points to specific ones set out in the articles that follow; it does not make every unenforceable expectation a natural obligation you may collect on. There must genuinely be a natural obligation behind the payment. Nor does the provision give you a right to demand payment — a natural obligation can never be enforced by action, so you could not have sued and cannot sue now for any balance. What it gives you is narrower but solid: the right to keep what was voluntarily paid, free from any claim for its return.
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.
- Jhonna Guevarra, et al. vs. Jan Banch, G.R. No. 214016, November 24, 2021 — read the decision on LawPhil →
- In the Matter of Urgent Petition for the Release of Prisoners on Humanitarian Grounds, G.R. No. 252117, July 28, 2020 — read the decision on LawPhil →
- Uniwide Sales Realty and Resources Corporation vs. Titan-Ikeda Construction and Development Corporation, G.R. No. 126619, December 20, 2006 — read the decision on LawPhil →