Short answer. In three situations: when you tell the seller you accept them; when, after delivery, you do anything with the goods that only an owner would do; or when you simply keep them past a reasonable time without telling the seller you are rejecting them. Silence plus possession counts as acceptance.

What the law says

when, after the lapse of a reasonable time, he retains the goods without intimating to the seller that he has rejected them

Civil Code, Article 1585 — When the Buyer Is Deemed to Accept. Read the full provision →

Acceptance can happen without you saying yes

Buyers usually picture acceptance as signing something. The Civil Code is broader. Telling the seller you accept is only the first of three routes, and it is the least common in real disputes. The other two happen by conduct and by inaction. That is the trap: a buyer who is unhappy with a shipment but says nothing, or who starts using it while deciding what to do, may find he has accepted it in law without ever intending to. If goods arrive short, damaged or off-specification, the safe move is a written rejection to the seller, dated, before anything else happens.

Acts inconsistent with the seller's ownership

Once goods are delivered, doing any act in relation to them which is inconsistent with the ownership of the seller is acceptance. The classic examples are reselling them, consuming them, incorporating them into something else, altering them, or pledging them as security. All of these treat the goods as yours. Simple inspection is a different matter — a buyer is entitled to examine what arrived — but the line between inspecting and using is thin, and it is drawn on facts. A buyer who breaks seals, mixes stock into inventory, or ships the goods onward to his own customer has usually crossed it.

The reasonable-time rule

The third route needs no act at all. Retaining the goods after a reasonable time without intimating rejection is acceptance. The Code deliberately does not give a number of days, because what is reasonable depends on the goods and the trade: perishables demand a response in hours, complex machinery may fairly take longer to test. What is never reasonable is indefinite silence while the goods sit in your warehouse. If you need time to test, say so to the seller in writing and record that the goods are held subject to inspection. That single message is often the difference between a live claim and a dead one.

Why acceptance matters, and what it does not kill

Acceptance generally makes the price payable and closes the door on rejecting the delivery outright. It does not automatically extinguish every claim: the Civil Code's rules on warranty against hidden defects, and any express warranty in the contract, run on their own terms and their own periods, which are short. So a buyer who has accepted may still have a remedy for a latent defect he could not have discovered on reasonable examination — but he has lost the simpler right to hand the goods back. Because the periods are unforgiving, anyone with a defective delivery should get advice quickly rather than negotiating with the supplier for months.

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.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.