400電(dian)(dian)話(hua)是(shi)一(yi)種主(zhu)(zhu)被叫(jiao)分攤付(fu)費的業(ye)務(wu)，主(zhu)(zhu)要用于企(qi)(qi)業(ye)接(jie)聽客戶(hu)來電(dian)(dian)。它本(ben)身并(bing)不(bu)(bu)支持主(zhu)(zhu)動外(wai)呼(hu)，也就是(shi)說，400電(dian)(dian)話(hua)號碼不(bu)(bu)能(neng)(neng)(neng)用于撥打出去。400電(dian)(dian)話(hua)主(zhu)(zhu)要是(shi)為了方(fang)便客戶(hu)聯系(xi)(xi)企(qi)(qi)業(ye)，提供售(shou)后服務(wu)、咨詢等服務(wu)。如果需要進行(xing)外(wai)呼(hu)，企(qi)(qi)業(ye)通常(chang)會(hui)(hui)使(shi)用其(qi)他的電(dian)(dian)話(hua)線路或者手(shou)機號碼。不(bu)(bu)過，一(yi)些企(qi)(qi)業(ye)可(ke)能(neng)(neng)(neng)會(hui)(hui)選擇使(shi)用呼(hu)叫(jiao)中心系(xi)(xi)統(tong)，結合400電(dian)(dian)話(hua)，來實現自動外(wai)呼(hu)功(gong)能(neng)(neng)(neng)，但(dan)這并(bing)不(bu)(bu)是(shi)400電(dian)(dian)話(hua)的基本(ben)功(gong)能(neng)(neng)(neng)，而是(shi)通過第三方(fang)服務(wu)提供商額外(wai)設置的。