Invalid. A contract signed and sealed by one party is generally invalid in law. However, if the party who signed and sealed regards the text as a valid offer, the other party who did not sign and seal only needs to make a valid commitment to the text, and the contract will be deemed valid. It is established in accordance with the law and takes effect accordingly without violating any legal provisions.

In addition, in fact, if the party who has not signed or stamped the contract has performed the contract and has recognized the content of the contract in his behavior, the contract is a valid contract. The Contract Law stipulates that if the law stipulates that a contract must be concluded in writing but the parties have not done so but one party has performed its main obligations and the other party has accepted it, the contract shall be established.

In other words, although the law requires a written form and there is no written contract between the parties, if one party has performed its main obligations and the other party has accepted it, the contract is deemed to be established. Then this situation can be applied by analogy to a situation where only one party signs. If only one party signs, but one party has performed its main obligations and the other party has accepted it, the contract is also considered to be established