1. Inquiry in official website, State Taxation Administration of The People's Republic of China, People's Republic of China (PRC): Go to official website, State Taxation Administration of The People's Republic of China, People's Republic of China (PRC), click "Online Tax Service", enter the "Tax Registration Information Inquiry" interface, and enter information such as enterprise name, registration number and unified social credit code to find the tax registration number after the integration of the three certificates.
2. Consultation at the window of the local tax bureau: Bring the business license, organization code certificate and other documents to the window of the local tax bureau, and consult the staff to inquire about the tax registration number after the integration of the three certificates.
3. Inquire through the tax service hotline 12366: dial the tax service hotline 12366, select "tax registration", and enter relevant information according to the prompts to find the tax registration number after the integration of the three certificates.