Is the contract signed by the owner of the house valid?

Legal analysis: the seller's contract signed by a non-homeowner is invalid. Because it is not the owner who signs the seller's contract, it is an act that has no right to dispose of it. Without the ratification of the person who has the right to dispose of it, the act is invalid. As a special kind of property, real estate should be registered. Therefore, even if the real owner does not find that he has no right to dispose of it, he will not be able to transfer ownership smoothly when he finally handles the transfer registration because the name on the real estate license does not match.

Legal basis: Article 171 of the Civil Law of People's Republic of China (PRC) (hereinafter referred to as "Civil Law"), if the actor has no agency, exceeds the agency or still acts as an agent after the agency is terminated, it will have no effect on the principal without ratification by the principal. The counterpart may urge the principal to ratify it within 30 days from the date of receiving the notice. If the trustor fails to declare it, it shall be deemed as refusal to ratify it. Before the act committed by the actor is ratified, the bona fide counterpart has the right to revoke it. Revocation shall be made by notice. If the act committed by the actor is not ratified, the bona fide counterpart has the right to demand the actor to perform the debt or demand the actor to compensate for the damage he has suffered. However, the scope of compensation shall not exceed the benefits that the counterpart can obtain when the principal ratifies. If the counterpart knows or should know that the actor has no right to act as an agent, the counterpart and the actor shall bear the responsibility according to their respective faults.