Mobile country code Thailand

520 00    my" CAT 3G 850                  CAT Telecom
520 01    AIS GSM 900                       Advanced Info Service
520 02    CAT CDMA 800                    CAT Telecom
520 03    AIS 3G 2100                        AWN
520 04    True Move H 3G/4G 2100       Real Future
520 05    dtac 3G 2100                       DTN
520 15    TOT 3G 2100                       Telephone Organization of Thailand (TOT)
520 18    Dtac GSM 1800                     Total Access Communication
520 23    AIS GSM 1800                      DPC
520 99    True Move GSM 1800             True Corporation
520 25    WE PCT PHS 1900                 True Corporation

credit  http://en.wikipedia.org/wiki/Mobile_Network_Code