It refers to the act of writing off the original invoice after sales returns, invoicing errors, taxable services are suspended, etc. During this process, if there is no original ticket copy information in the general administration’s ledger system, the red flush will fail. The State Administration's ledger system refers to the electronic ledger system of the State Administration of Taxation, which is responsible for recording all tax information, including invoice information. When performing a red flush operation, the General Administration's ledger system cannot receive the copy information of the original ticket, which will cause the red flush to fail.