Short answer. Yes. When the intention behind a contract is in doubt, the law says the parties' acts at the time of signing and afterwards are to be principally considered. How both sides actually performed the agreement is powerful evidence of what they meant it to say.
What the law says
In order to judge the intention of the contracting parties, their contemporaneous and subsequent acts shall be principally considered.
Civil Code, Article 1371 — Contemporaneous and Subsequent Acts. Read the full provision →
Conduct is evidence of intention, not a licence to rewrite
The rule is about proving intention, not about replacing the document. Two adjectives carry the weight: contemporaneous acts are what the parties did around the time the contract was made — the negotiations, the drafts exchanged, the first payment, the handing over of keys. Subsequent acts are what they did afterwards while performing it. The law directs that these be principally considered, which is strong language; it places behaviour at the centre of the inquiry rather than treating it as a footnote. But the doorway to this inquiry is doubt. Where the words of the agreement are clear and leave no question about what the parties intended, there is nothing to interpret, and conduct cannot be used to smuggle in a different bargain.
What this looks like in a real dispute
The pattern is familiar. A paper calls itself a deed of sale, but the supposed seller stayed in possession, kept paying the taxes, and the buyer collected monthly amounts that look like interest — that behaviour is evidence the parties really intended a loan secured by the property. Or a written lease is silent on who pays for major repairs, and for six years the owner paid every one of them without protest. Or an agreement fixes a delivery date, yet both sides routinely accepted late deliveries without complaint. In each situation the question is the same: what did the people who signed this actually understand themselves to be agreeing to?
The limits worth knowing before you rely on this
Three limits catch people out. First, conduct interprets an ambiguity; it does not cure a contract that is void for illegality or for want of a form the law requires. Second, it must be the conduct of both parties or of the party now taking the opposite position — your own private understanding, never communicated and never acted on jointly, proves little. Third, isolated tolerance is weak. One waived late payment is an accommodation; a consistent practice sustained over years is a pattern. And a contract that expressly says indulgence shall not be treated as waiver will be held against the party invoking it.
Build the record now
Because this rule runs on evidence, the practical work is documentary. Gather the receipts, the transfers, the messages arranging each performance, the tax declarations, the utility bills, the emails where someone acknowledged an obligation. Dates matter, because a course of dealing is proved by repetition over time. If you are the one who has been quietly accommodating the other side, put your position in writing now so the pattern does not harden further. How much weight a court gives any of this depends on the whole record; this is general information about the rule, not an assessment of your contract.
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.
- Spouses Salvador Abella and Alma Abella vs. Spouses Romeo Abella and Annie Abella, G.R. No. 195166, July 8, 2015 — read the decision on LawPhil →
- Planters Development Bank (Now China Bank Savings, Inc.) vs. Fatima D.G. Fuerte, G.R. No. 259965, October 7, 2024 — read the decision on LawPhil →
- Captain Ramon R. Verga, Jr. vs. Harbor Star Shipping Services, Inc, G.R. No. 261323, November 27, 2024 — read the decision on LawPhil →
- Public Estates Authority vs. Henry Sy, Jr, G.R. No. 210001, February 6, 2023 — read the decision on LawPhil →