The seal of the tripartite agreement unit can also take effect without signature. The tripartite agreement shall come into effect after being signed or sealed by three parties, so the tripartite agreement is not signed, but the sealed tripartite agreement is also valid.

According to the Civil Code, if the parties to a contract do not sign, the contract will not be established, and the contract that is not established is not legally binding, so there will be no breach of contract and no liability for breach of contract can be investigated.