Unmarried Cohabitation: Proving Joint Contribution for Property Co-Ownership

When unmarried partners separate, a frequent question is who owns the property acquired during their relationship. The Supreme Court’s decision in Atienza v. De Castro provides a clear answer where one partner is already married: co-ownership exists only to the extent of proven actual joint contribution. A claim of ownership must rest on evidence, not on assumptions about financial capacity.

The Facts of the Case

In 1983, Lupo Atienza, then president and general manager of two shipping corporations, hired Yolanda de Castro as an accountant. Their professional relationship turned intimate, and despite Lupo being married to another woman, the two lived together and had two children.

In 1987, Yolanda purchased a property in Bel-Air Subdivision, Makati, under a contract to sell and later a deed of transfer in her name. After the relationship ended, Lupo filed a complaint for judicial partition, claiming the property was acquired with his exclusive funds and should therefore be co-owned.

Yolanda denied this, insisting she bought the property for P2.6 million using her own savings and earnings as a certified public accountant and businesswoman.

The Issue

Was Lupo entitled to a share of the property as a co-owner by virtue of his cohabitation with Yolanda?

The Applicable Law: Article 148 of the Family Code

The Court first settled which property regime governs the relationship. Since Lupo was validly married to another woman, he and Yolanda were not capacitated to marry each other. Their cohabitation fell under Article 148 of the Family Code, not the more general co-ownership rule of Article 144 of the Civil Code.

Article 148 covers cohabitation in bigamous or adulterous relationships. Under this provision, only properties acquired by both parties through their actual joint contribution of money, property, or industry may be owned in common, in proportion to their respective contributions. If no proof of the extent exists, the contributions and shares are presumed equal — but proof of actual contribution is still required.

Lupo argued that Article 144 applied, which would presume co-ownership even without proof of contribution. The Court rejected this. Article 148 was enacted precisely to fill the gap left by Article 144, and it applies even if the cohabitation began before the Family Code took effect.

Burden of Proof and the Evidence

The Court reminded Lupo that in civil cases, the party asserting an affirmative claim bears the burden of proof. A mere allegation is not evidence. The plaintiff must rely on the strength of his own case, not on the weakness of the defense.

Lupo failed to prove that he actually contributed funds to the purchase. His evidence consisted mainly of bank records showing withdrawals from his corporations’ dollar accounts and arguments that Yolanda lacked financial capacity. The Court found these irrelevant to the actual purchase of the property.

In contrast, Yolanda presented the contract to sell, deed of assignment, and deed of transfer — all entered into by her alone, to the exclusion of Lupo. She also showed bank statements, promissory notes, and evidence of her business dealings in foreign currency trading, money lending, and jewelry retail. These established both her financial capacity and her sole acquisition of the property.

The Court held that although a certificate of title does not absolutely foreclose co-ownership, co-ownership under Article 148 arises only where actual joint contribution is proven. Since Lupo presented no such proof, the appellate court correctly declared Yolanda the exclusive owner.

The Ruling

The Supreme Court denied Lupo’s petition and affirmed the Court of Appeals’ decision. The property was declared exclusively owned by Yolanda de Castro.

Practical Takeaways

• Proof matters. Under Article 148 of the Family Code, a partner who is married to another must show actual joint contribution of money, property, or industry to claim a share of property acquired during cohabitation.
• Keep documentary evidence. Contracts, receipts, bank transfers, and title documents naming the contributor will generally determine ownership. A title in one partner’s name creates a strong presumption of that partner’s ownership.
• Financial capacity is not a substitute for proof. Showing that one partner was richer or had access to funds does not prove that those funds were used to buy the property. Evidence must trace the actual source of payment.
• Article 148 may apply retroactively. Even if cohabitation began before the Family Code took effect, Article 148 governs property relations of parties living in adulterous or bigamous relationships.
• Beware of pleadings alone. A complaint alleging co-ownership must be supported by competent evidence; the burden never shifts merely because the defendant appears to have a weaker financial standing.

This article is general information and not legal advice. For your specific situation, consult a lawyer or ask ASG Legal AI.