Are all the numbers beginning with 400 legal?

400 telephone is mainly wired telephone, which is generally used for enterprise customer service. All are officially registered and legal, but not all are legal. It is recommended not to answer the phone starting with 400, because it is generally used as a consultation phone, and the main function of 400 phone is to share business with the called party. 400 telephone is a called shared service, that is, the calling party bears the local telephone access fee and the called party bears all the incoming call answering fees. At present, it has been widely used in multi-industry pre-sales and after-sales service consultation. 400 telephones are divided into 4006 (China Unicom), 4007 (China Mobile's former Tietong), 4008 (China Telecom), 400 1 (China Mobile's new section), 4000 (China Unicom's new section) and 4009 (China Telecom's new section). The 400 telephone is a virtual phone switchboard designed for enterprises and institutions with unified numbers all over the country. All incoming calls to the 400 switchboard number are transferred to the preset fixed telephone, mobile phone or call center line. The 400 telephone switchboard is only responsible for handling incoming calls, not outgoing calls. Telephone charges are shared by enterprises and users who dial 400, and callers only pay local telephone charges. The 400 hotline embodies the sense of enterprise service and is a symbol of credibility and strength. 5G+ 1000M broadband is free to use, intelligent double gigabit, and good life is customized. For details, please visit the online business hall of Guangxi Telecom, and customer service 156 will answer your questions.