Hello, under normal circumstances, all contracts need to be signed and sealed, but if there is only one, the contract is also legally binding. Article 32 of the Contract Law stipulates: "If the parties conclude a contract in the form of a contract, the contract is established when both parties sign or seal it." The relationship between signature and seal in this article is optional, that is, the parties can sign without seal, seal without signature, or both. The signature and seal of both parties can be done at the same time and place, or in different places. If the contract is completed in a different place, the time when the last party completes the signature or seal shall be the time when the contract is established.