Talk:Thailand/@comment-99.51.75.44-20141207091416/@comment-24682153-20141207130008

Yes, you can move or "port", but you should better be low on credit on your old SIM when porting. The feature you mention is called Mobile Number Portability. More about it in Englisch: and it should work with dtac accordingly. The standard fee for MNP in Thailand is 29 THB.
 * from True
 * from AIS