Legal analysis: After the mortgage is settled, the parties need not return the purchase contract. Because when buying a house, the contract is signed in quadruplicate, that is, from the date of signing, the owner must have an original buyer's contract and an original commercial housing agreement, one for the general developer, one for the owner, one for the bank as a loan, and one for the real estate management bureau as a registration record. The purchase contract is a very important document, and it is also very useful; For example, developers need to provide all purchase contracts to apply for real estate licenses. If the purchase contract lacks a copy, the real estate license will not be processed. In addition, before handling the real estate license, you must provide a purchase contract before applying for the purchase of a house to withdraw the provident fund and settle down.

Legal basis: Article 25 of the General Principles of Loans. If the borrower needs a loan, he should apply directly to the host bank or the agent bank of other banks. The borrower shall fill in the loan application, including the loan amount, loan purpose, repayment ability and repayment method, and provide the following information: 1. Basic information of the borrower and guarantor; Two, the financial department or accounting (audit) firm approved the last year's financial report, as well as the previous financial report to apply for loans; Three, the original unreasonable occupation of loans to correct the situation; 4. List of collateral and pledge, as well as the certificate that the person who has the right to dispose of the collateral and pledge agrees to guarantee, and the relevant documents that the guarantor agrees to guarantee intention; V. Project proposal and feasibility report; Other relevant information deemed necessary by the lender.