Short answer. Only to repel an intrusion that is happening now or about to happen, and only as much force as is reasonably necessary. Article 429 protects the owner or lawful possessor who pushes back at the moment of the invasion. It gives no right to remove someone already settled in.
What the law says
he may use such force as may be reasonably necessary to repel or prevent an actual or threatened unlawful physical invasion or usurpation of his property
Civil Code, Article 429 — Doctrine of Self-Help. Read the full provision →
The doctrine of self-help, and the moment it lives in
Article 429 is the Civil Code's doctrine of self-help. It lets an owner or lawful possessor exclude others and, for that purpose, use such force as may be reasonably necessary to repel or prevent an actual or threatened unlawful physical invasion or usurpation. Read the two adjectives carefully. The invasion must be actual, meaning it is happening, or threatened, meaning it is imminent. Self-help is a right to hold a line, not a right to redraw one. Once the intruder is in and settled, nothing is being repelled or prevented any more, and the article simply stops supplying an answer.
Why this does not cover the occupant who overstayed
This is the assumption most readers arrive with, and it is the wrong one. A tenant who stopped paying, a relative who overstayed, a buyer whose sale collapsed: none of them entered by an unlawful physical invasion. They entered lawfully, with your permission, and what has ended is their right to remain. Changing the locks, cutting the water or the power, removing their belongings, or posting people at the gate to keep them out is not self-help under Article 429. Recovering possession from someone who came in with consent is a court matter, and treating it as a self-help matter is how an owner with a strong case ends up as the respondent.
Reasonably necessary is measured against the intrusion
The force allowed is measured against what the specific intrusion requires, and no further. Someone climbing your fence at night and someone standing at your gate arguing do not justify the same response. Anything beyond what the moment demanded stops being protected by the article and becomes your own act to answer for, whatever the intruder was doing. The safest instinct here is also the legally sound one: use the least that works, stop when the intrusion stops, and record what happened, including photographs, the time, who was present, and any report you made about it.
What to do instead
If the person is already in possession, the useful questions are how they got there and how long ago, because those decide which action you bring and how much time you have to bring it. Gather the document that gave them entry if one exists, the date it ended, and any written demand you have made for them to leave. If an intrusion is happening right now and could turn physical, calling the police is the better move than escalating it yourself. Article 429 will not retroactively excuse a response that the moment did not require, and the record of who escalated tends to survive.
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.
- North Greenhills Association, Inc. vs. Atty. Narciso Morales, G.R. No. 222821, August 9, 2017 — read the decision on LawPhil →
- Philippine Bank of Communications, et al. vs. Elenita B. Trazo, G.R. No. 165500, August 30, 2006 — read the decision on LawPhil →
- United Coconut Planters Bank, et al. vs. Ruben E. Basco, G.R. No. 142668, August 31, 2004 — read the decision on LawPhil →
- Reynaldo Villafuerte, et al. vs. Hon. Court of Appeals, et al, G.R. No. 134239, May 26, 2005 — read the decision on LawPhil →