Ban gap rac roi khi khong biet thong tin ca nhan sim cua minh dang su dung ? De lay lai cac thong tin nhu : chu so huu,ngay thang nam sinh,so CMTND... ban lam nhu sau:
+Viettel:soan tin nhan TTDK gui 141
+Vinaphone:soan tin nhan TTTB gui 1414
+Mobiphone:saon tin nhan TT gui 1414
