If the developer repeatedly delays the delivery time and encounters a "bad completion" crisis, the home buyer must not check out according to the agreement in the purchase contract. Because the developer no longer has much money in hand at this time, after checking out, he cannot get the purchase money immediately, he can only get a receipt or an IOU. The relationship between home buyers and developers will change from a buyer-seller relationship to a creditor-debt relationship.

Real estate certificate (PremisesPermit) is a document that the buyer obtains the legal ownership of the house through a transaction and can exercise the rights to possess, use, benefit from and dispose of the purchased house in accordance with the law. That is, the "House Ownership Certificate" is the legal certificate for the state to protect the ownership of the house in accordance with the law. Home owner credentials manage and use their own home. The real estate certificate includes the house ownership certificate and the house ownership certificate. In a normal sense, the real estate certificate is the abbreviation of the house ownership certificate. It is a written certificate issued by the real estate registration authority to prove the ownership of the house.