Generally speaking, as long as the contract is the true intention of both parties, and the contents of the contract do not violate the law, whether it is held by both parties or unilaterally, it does not necessarily affect the validity of the contract, so the contract held by only one party is valid.

In some cases, only one party holds the contract as evidence to prove the existence and content of the agreement. However, just holding a contract does not mean that the contract can be executed unilaterally. The contract also needs to comply with the provisions of the contract law and other relevant laws and be protected by the judicial organs.

On the legal level, all parties to a contract should enjoy the rights and obligations of the contract equally, and both parties or both parties should perform the terms stipulated in the contract. If one party unilaterally terminates the contract or fails to perform its contractual obligations, it may involve breach of contract and need to bear corresponding legal responsibilities.

A signed but not sealed contract is legal and valid.

A legally established contract is legally binding only after it is signed, not sealed.

According to the provisions of the Civil Code, if the parties conclude a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Therefore, signature, seal and fingerprint have the same legal effect. Therefore, the contract can only be established by signing, and the contract is established through the contract. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations and the other party accepts them.

A general contract does not have to be signed and sealed at the same time. It should be decided by both parties themselves, and the autonomy of the parties should be respected. As long as the authenticity of the signature is confirmed, the contract should be considered valid.

Reference to the above content: Baidu Encyclopedia-Civil Code