全国联通400电话申请：http://www.trust400.com/liantong/
这是以40060开头的400号码介绍页面。
该号段也写作400-60、4006-0、040060、0400-60、04006-0、0086-400-60、0086-4006-0、+86-400-60、+86-4006-0等形式。
400长途免费号码，也就是拨打时仅需支付当地市话费，长途电话费由该号码机主支付。
归属：由于400号码是全国通用的，该号码所处地方、机主资料不好确定，可以找所属运营商咨询：
该号段前四位为4006，是中国联通公司，可以拨打联通客服热线10010咨询详细情况。
组成：400号码由10位数字组成，40060后面可以是从00000至99999，也就是4006000000-4006099999。本号段的1000个6、7、8位索引列表如下：
400600:40060000-40060099
4006000:40060000,40060001,40060002,40060003,40060004,40060005,40060006,40060007,40060008,40060009
4006001:40060010,40060011,40060012,40060013,40060014,40060015,40060016,40060017,40060018,40060019
4006002:40060020,40060021,40060022,40060023,40060024,40060025,40060026,40060027,40060028,40060029
4006003:40060030,40060031,40060032,40060033,40060034,40060035,40060036,40060037,40060038,40060039
4006004:40060040,40060041,40060042,40060043,40060044,40060045,40060046,40060047,40060048,40060049
4006005:40060050,40060051,40060052,40060053,40060054,40060055,40060056,40060057,40060058,40060059
4006006:40060060,40060061,40060062,40060063,40060064,40060065,40060066,40060067,40060068,40060069
4006007:40060070,40060071,40060072,40060073,40060074,40060075,40060076,40060077,40060078,40060079
4006008:40060080,40060081,40060082,40060083,40060084,40060085,40060086,40060087,40060088,40060089
4006009:40060090,40060091,40060092,40060093,40060094,40060095,40060096,40060097,40060098,40060099