Legal analysis: required information: 1, invoice. Including the down payment invoice and the mortgage invoice issued by the developer after mortgage; 2. Purchase contract; 3. Deed tax certificate; 4. Loan agreement and mortgage guarantee agreement; 5. Pay the maintenance fund receipt; 6, natural gas, heating installation fees and other receipts.

Legal basis: Article 10 of the Administrative Measures for the Pre-sale of Urban Commercial Housing. Where commercial housing is pre-sold, the development enterprise shall sign a pre-sale contract with the winning bidder. The development enterprise shall, within 30 days from the date of signing the contract, go to the real estate management department and the land management department of the people's government of the city or county to handle the registration and filing procedures for the pre-sale contract of commercial housing. Real estate management departments should actively apply network information technology and gradually implement online registration and filing of commercial housing pre-sale contracts. Commercial housing pre-sale contract registration procedures can be entrusted to an agent. If an agent is entrusted, there shall be a written power of attorney.