Legal analysis: The real estate certificate number is the number located on the second page of the big red book. It has two names, which have to be distinguished according to different versions.

Legal basis: "People's Republic of China and Civil Code"

Article 599 The seller shall deliver the subject matter for withdrawal to the buyer in accordance with the agreement or transaction customs Relevant documents and information other than documents.

Article 600: When a subject matter with intellectual property rights is sold, the intellectual property rights of the subject matter do not belong to the buyer, unless otherwise provided by law or otherwise agreed by the parties.

Article 601: The seller shall deliver the subject matter according to the agreed time. If a delivery period is agreed upon, the seller may deliver at any time within the delivery period.