Legal analysis: 1, preparation materials, the buyer and the seller should prepare complete materials, such as the original house ownership certificate, the original owner's ID card, the original owner's household registration book, the owner's first-class bank card, etc. If the house is delivered, the seller also needs to provide a notice of change of the public houses purchased by the central unit in Beijing.

2. Take the number. On working days, the buyer and the seller bring materials to the housing management department of the residential area where the house is located to receive the online sign number.

3. Submission of materials: Both the buyer and the seller need to go to the designated window to submit materials and fill in relevant application forms.

4. After receiving the online signing contract, the online signing personnel will operate the online signing program in the online system to generate an online signing contract, which will be signed by the buyer and the seller.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 469 The parties may conclude a contract in writing, orally or in other forms.

Written form refers to contracts, letters, telegrams, telexes, faxes and other forms that can tangibly express the contents contained.

A data message that can tangibly express its content through electronic data interchange, e-mail, etc. , and can be retrieved at any time, are considered in writing.

Article 490 Where the parties conclude a contract in the form of a contract, the contract is formed when the parties sign, seal or fingerprint it. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.

A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.