Online signing refers to the online signing in the real estate field, that is, after the two parties sign the contract, they go to the relevant real estate departments for the record and publish it online. Then it will be given an online sign number, through which users can query online. Online signing is to make real estate transactions more transparent and prevent "one room selling more", which can be revoked after signing. The general "online signing" program is: 1. The two parties to the transaction shall negotiate and formulate relevant terms according to the text of the commercial housing deposit agreement or the sales contract published online; 2. Real estate development enterprises print the agreement or contract confirmed by both parties through the online signing system; 3. Signature (seal) of both parties; 4. Indicate on the electronic title certificate that the commodity house has been booked or signed. In the field of e-commerce, it can also be called electronic contracting and online contract signing. In order to prevent the intermediary from signing online without authorization, the Notice on Improving the Online Signing Process of the Stock House Sales Contract issued by the Municipal Commission of Housing and Urban-Rural Development stipulates that if the two parties to the transaction fail to sign or seal the contract and the real estate agency submits the online signing information without authorization, the online signing behavior of the agency or personnel will be restricted after verification, and its violations will be publicized and exposed, and serious violations will be recorded in the credit files of the agency and personnel.