This contract can only come into effect and have legal effect after being signed. The following are the requirements and steps for signing the contract: 1. Legal subject: The contracting parties must be legal subjects, that is, legal persons, companies or organizations. 2. Legitimate purpose: The contract must be signed for a legitimate purpose and cannot violate the law. 3. Expression of agreement: The signing of the contract must be an agreement reached by all parties voluntarily and cannot be obtained by coercion, deception, coercion or intimidation. 4. Determination of content: The content of a contract must be clear, definite and specific, which can be a written agreement or an oral agreement, but a written contract has more legal effect. 5. Integrity: The contract must be complete without omission or ambiguity. 6. Legal procedures: According to the law, some contracts need to be signed in accordance with specific procedures to have legal effect. For example, the house sales contract must be signed in the real estate trading center. When signing a contract, both parties shall negotiate voluntarily and on an equal footing according to law, fully understand and clarify the contents of the contract, and sign it after both parties are convinced that it is correct, so as to ensure the validity and legal effect of the contract. Before signing the contract, both parties should consult lawyers or relevant professionals to ensure the legality and effectiveness of the contract.