Heirs of King Si Biak, namely Albert King and Arthur King v. Panciteria Lido Chinese Cuisine Co. G.R. No. 279019, August 12, 2026 (Hernando, J., First Division) The Supreme Court reversed the Court of Appeals and the IPO Director General, reinstating the BLA's cancellation of PLCCC's trademark registrations (Nos. 4-2012-014828 and 4-2012-014829). It held that bad-faith registration over a known prior trade name defeats trademark rights, and that heirs of a deceased partner have standing to protect partnership property.

1. Trademark

Rule: Under Section 122 of the IP Code, trademark ownership is acquired through valid registration, not prior use. However, registration must be "made validly."

Application: PLCCC's registration of the "Lido" marks was not validly obtained because it was procured in bad faith. Its partner, Alipio, had personal knowledge that the right to the "Panciteria Lido" mark belonged to Eng Son Co., not to her individually. Under Article 1821 of the Civil Code, a partner's knowledge is imputed to the partnership. Since PLCCC knowingly registered a mark it knew belonged to another entity, its registration was void and subject to cancellation under Section 151.1(b) of the IP Code (registration obtained fraudulently or contrary to law).

2. Trade Name

Rule: Section 165.2 of the IP Code protects a trade name whether or not registered, against any subsequent use by a third party likely to mislead the public.

Application: Eng Son Co. had used "Lido," "Panciteria Lido," and "Lido Restaurant" as its trade name for decades (since 1936). By registering trademarks built around the same dominant "Lido" identity, PLCCC appropriated Eng Son Co.'s protected trade name, independently justifying cancellation of its marks even setting the bad-faith issue aside.

3. Succession

Rule: Partnership property remains partnership property until liquidation and winding up are completed (Civil Code, Arts. 1829, 1830[5], 1841); a deceased partner's proprietary interest passes to his heirs by succession (Arts. 777, 1841).

Application: King Si Biak's death dissolved but did not terminate Eng Son Co.; no liquidation or winding up ever occurred, so the "Lido" mark remained partnership property, and Alipio could not claim exclusive ownership over it. King Si Biak's proprietary interest passed to his heirs (the King brothers) upon his death, giving them sufficient legal standing to file the cancellation petitions, contrary to the IPO Director General's ruling that only PLCCC (not Eng Son Co.) had standing.