Legal analysis: you need to write a receipt and indicate the purpose of collection. Legal basis: Article 36 of People's Republic of China (PRC) Urban Real Estate Management Law states that when real estate is transferred or mortgaged, the parties concerned shall register the ownership in accordance with the provisions of Chapter V of this Law. Article 62 When a real estate is mortgaged, it shall be registered with the department designated by the local people's government at or above the county level. Where the land use right and house ownership are obtained due to the disposal of mortgaged real estate, the transfer registration shall be handled in accordance with the provisions of this chapter.