Legal analysis: A legally established contract is valid only if its seals overlap. The parties may agree to issue a certificate to prove the validity of the contract. Generally, except for a contract concluded by one party through fraud or coercion that harms the interests of the state, maliciously colludes, harms the interests of the state, the collective or the third party, and violates the mandatory provisions of laws and administrative regulations, the contract will take effect immediately.

Legal basis: Article 490 of the Civil Code of People's Republic of China (PRC). If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.