1. In principle, natural persons must have full capacity to sign contracts. If a person with limited capacity and a person without capacity cannot sign a contract in person, their legal representatives shall sign it on their behalf.
2. For a non-natural person, it is necessary to have the ability to conclude a contract after the legal procedure is established.
(II) The parties' expression of will is true: if the expression of will is untrue, the impact on the effectiveness of the contract shall depend on the specific circumstances, including the following situations:
1. In case of general misunderstanding, the contract is still valid.
2. If there is any major misunderstanding, this contract can be modified or terminated.
3. If the contract is made in obviously unfair by taking advantage of the danger of others, the contract may be modified or terminated.
4. The contract is invalid if it is established by fraud or coercion and damages the interests of the state; If it does not harm the interests of the state, the contract can be changed or terminated.
(3) It does not violate laws or public interests.
(4) The object of a contract must be definite and possible: the object of a contract determines the quality and quantity of the rights and obligations of the contract. Without it, the contract will lose its purpose and positive significance and should be invalid.
Legal basis: Civil Code of People's Republic of China (PRC).
Article 133 A civil juristic act is an act in which a civil subject establishes, changes or terminates a civil juristic relationship through expression of will.
Article 134 A civil juristic act may be established unanimously based on the will of two or more parties, or unilaterally.
If a legal person or an unincorporated organization makes a resolution in accordance with the way of discussion and voting procedures stipulated by law or articles of association, the resolution is established.
Article 135 A civil juristic act may be in written form, oral form or other forms; Where laws and administrative regulations stipulate or the parties agree to adopt a specific form, it shall adopt a specific form.
Article 136 A civil juristic act shall take effect upon its establishment, except as otherwise provided by law or agreed by the parties.
Without the legal provisions or the consent of the other party, the actor may not change or terminate the civil juristic act.