Short answer. Then the seller is not answerable for it. The Civil Code provides that where adverse possession began before the sale but the prescriptive period was completed after the transfer, the vendor shall not be liable for eviction. The clock ran out on your watch, so the loss is treated as yours.
What the law says
When adverse possession had been commenced before the sale but the prescriptive period is completed after the transfer, the vendor shall not be liable for eviction.
Civil Code, Article 1550 — Prescription Completed After Sale. Read the full provision →
Why the rule is harsh, and logical
Every sale carries an implied warranty against eviction: if a buyer is deprived of the thing by a final judgment based on a right existing before the sale, the seller answers for it. Article 1550 of the Civil Code carves out one situation from that protection. Acquisitive prescription is not an event but a period, and the law asks who was in a position to stop it. Once the property is yours, you are the one who can eject the occupant, demand rent, put up a fence, or file suit — any of which interrupts the running of the period. If you did none of those and let the years complete, the law places the consequence on you rather than on the seller who no longer had standing to act.
The dividing line: when did the period finish?
Everything turns on a date. If the occupant's possession had already ripened into ownership before you bought, you acquired a title that was defective from the start and the warranty against eviction is in play. If the period only completed after the transfer, this article closes that door. So the first task in any such dispute is to establish precisely when the adverse possession began and what character it had, because the periods differ — possession in good faith with just title runs shorter than possession without either, and the applicable period for immovables depends on which of those the occupant can prove.
What the article does not excuse
It relieves the seller of the eviction warranty, and nothing more. It does not licence a seller who actively concealed the occupation, who represented the lot as vacant and clean, or who made a specific promise about possession in the deed — misrepresentation and fraud are separate matters with separate remedies. It has no bearing on a defect of a different kind, such as a hidden encumbrance or a double sale. And note the practical limit of prescription itself: land registered under the Torrens system is generally not lost by adverse possession at all, so if your property is titled, the occupant's real problem may be that the clock never ran.
If someone is occupying land you have bought
Treat time as the enemy and act rather than negotiate indefinitely. Inspect the property before you buy, not after — an ocular inspection showing houses, crops or fences on the lot is worth more than any assurance in a deed. If you already own it and find someone in possession, demand in writing that they vacate, keep proof of service, and do not accept payments or arrangements that quietly recognise their claim. Ejectment actions carry short deadlines of their own, measured from dispossession or from demand. Before you decide whether to sue the occupant, the seller, or both, have the title, the deed and the history of possession reviewed; you can book a consultation with us.