The official seal of the contract has legal effect. A contract can be stamped with the official seal or the contract seal. If both parties reach an agreement through consultation and the official seal of the contract is valid, the contract has legal effect. If the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign or seal it. 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.