400 telephone is not a free call, but a shared service between the calling party and the called party, 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).
400 telephone is mainly used as an enterprise, and the applicant needs the company main body. However, many enterprises use 400 phones for marketing, so 400 phones account for a very large proportion of users' complaints about harassing calls.
At the same time, some criminals use the credibility of 400 to let users reduce their awareness of protection through telephone fraud. There are many cases of 400 phone fraud. Please pay attention to screening when answering such calls. When the other party prompts for verification code, transfer, refund, winning prizes, subsidies, or involves such cases, there is a great possibility of fraud, so we must verify it in many ways to prevent fraud!