The invoice itself is legal, but it violates the regulations in the process of issuing, obtaining and using, such as: falsely issuing invoices and not issuing invoices at one time according to the prescribed time limit, order and column; Not stamped with the special invoice seal; Expand the scope of invoice use; Invoice across designated areas; The contents of the bill are untrue; Blurred handwriting on the ticket face, etc. The above situation is based on taxable business activities, so it can be characterized according to the "Measures for the Administration of Invoices in People's Republic of China (PRC)" or "Accounting Law of People's Republic of China (PRC)" and the specific situation and the severity of the problem.