Short answer. It is presumed. You do not have to prove that your contract had a cause, or that the cause was lawful, even if the document never says why the parties agreed. The burden sits on the debtor who claims otherwise, and it is that person who must prove it.
What the law says
Although the cause is not stated in the contract, it is presumed that it exists and is lawful, unless the debtor proves the contrary.
Civil Code, Article 1354 — Presumption of Cause. Read the full provision →
Silence in the document is not a gap in your case
Article 1354 of the Civil Code is short and blunt: although the cause is not stated in the contract, it is presumed that it exists and is lawful, unless the debtor proves the contrary. Cause is the reason each side entered the agreement — the price for the seller, the thing for the buyer, the service for the one who pays for it. Many private documents in the Philippines never spell this out. A one-page deed of sale, an acknowledgment of debt, a promissory note written by hand: none of them usually explain why the obligation was assumed. That silence does not weaken the instrument. The law fills the space for you.
Who has to prove what
The practical effect is a shift in burden, and that is usually what decides these disputes. If you are suing to enforce a written contract, you prove the contract and the breach. You are not obliged to open the history of the transaction and demonstrate that a real, lawful reason existed behind it. The person resisting the obligation — the debtor — must come forward with evidence that there was no cause at all, or that the stated or hidden cause was contrary to law, morals, good customs, public order or public policy. Bare denial does not do it. Saying "I signed but I got nothing" is an allegation, not proof, and an allegation that fails leaves the presumption standing.
What the presumption does not cover
The presumption is about cause, not about everything else. It does not prove that you and the other party actually consented, that the signature is genuine, that the object of the contract exists, or that the required form was followed where the law demands one. It does not cure a contract that a statute independently declares void. It is also rebuttable, not conclusive — evidence of a false or unlawful cause, of a simulated transaction, or of an agreement with no consideration behind it can still defeat it. And it protects the contract, not any particular amount you claim under it; sums, interest and damages must still be proved in the ordinary way.
What this means if you are the one being sued
If you are the debtor and you believe the document you signed rests on nothing, understand what you have taken on. You carry the burden, and the case will turn on documents and conduct rather than on your account of events. Gather bank records, receipts, messages and anything showing that no money or benefit ever moved, and note who else witnessed the signing. If the true reason for the agreement was unlawful, that is a distinct defence with its own consequences, some of which may leave neither side able to recover. Bring the paperwork and the timeline to a lawyer before you file or answer, because the framing of that defence shapes everything after it.
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.
- Ricardo V. Quintos vs. Development Bank of the Philippines, et al, G.R. No. 168258, August 17, 2015 — read the decision on LawPhil →
- Dioscoro Poliño Bacala, substitute Judicial Guardian of Incompetent Aquilino O. Poliño vs. Heirs of, G.R. No. 200608, February 10, 2021 — read the decision on LawPhil →
- Generoso Sepe vs. Heirs of Anastacia Kilang, rep. by her children Maria, Donata, Feliciana,... B.M. No. 3288 April 10, 2019 Mercuria D. So vs. Ma. Lucille P. Lee, G.R. No. 199766, April 10, 2019 — read the decision on LawPhil →
- Dr. Rico Vargas Substituted By His Wife, Cecilia Vargas And Children, Namely: Richelle Josie Judy Vargas-castro, Arvee T. Vargas And Cecilia Vargas, vs. Jose F. Acsayan, Jr, G.R. No. 206780, March 20, 2019 — read the decision on LawPhil →