Legal analysis: receipt, the down payment of house purchase is to open a receipt. When handing over the house, the housing surveying and mapping department will conduct on-the-spot measurement of the housing area to obtain an accurate housing area, and the actual sales price of the house will be accurate, and the developer will issue a formal purchase invoice.

Legal Basis: Interpretation of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Disputes over Commercial Housing Sales Contracts Article 21 If one party requests to confirm the invalidity of the commercial housing sales contract or to dissolve or terminate the contract, if the secured party files a lawsuit as a third party with independent claim, it shall be tried together with the disputes over the commercial housing secured loan contract; If no lawsuit is filed, only disputes over commercial housing sales contracts will be handled. If the guaranteed party files a separate lawsuit against the contract dispute of commercial housing secured loan, it can be tried together with the dispute of commercial housing sales contract. If the Commodity House Purchase and Sales Contract is confirmed invalid or cancelled or dissolved, and the Commodity House Guaranteed Loan Contract is also dissolved, the seller shall return the principal and interest of the house purchase loan and the purchased house price to the guarantor and the buyer respectively.