1. First of all, it is necessary to distinguish between national tax invoices and local tax invoices, which can be distinguished from the "National Uniform Invoice Producer Seal" on the face. If the seal is printed with the words "Producer of Provincial State Taxation Bureau" or "Producer of Municipal State Taxation Bureau", enter the website of the provincial or municipal State Taxation Bureau for inquiry; If the seal has the words "produced by the local taxation bureau of _ _ province" or "produced by the local taxation bureau of _ _ city", enter the website of the local taxation bureau of this province or city for inquiry. You can search the website directly in Chinese. If you want to inquire about the sales invoices issued by our company for customers, you can directly search in Chinese and enter the website of Dongguan State Taxation Bureau. 2. After entering the tax bureau website, the pages of different tax bureau websites will be different. However, when you want to view invoices, you usually click on the words "invoice query", "invoice inspection" and "invoice comparison" to enter the query. After clicking, an interface will pop up asking for invoice information. Enter relevant information according to the prompt, and then click OK and Query to pop up the query result, usually with invoice purchase information. If there is something wrong with the invoice, words such as "Our Bureau has never sold this invoice", "No invoice found" and "No record found" will generally appear. 3. You can call the national unified tax service hotline (area code+12366) for consultation and inquiry. 4. Confirm whether the other party has a legal invoice purchase record by providing a copy of the invoice purchase record containing the invoice code in the invoice purchase book.