Last name ตั้งใจ (Tangchai 
, Inted 
, Intain ) , across the world, is a rare surname. The family name ตั้งใจ is characteristic of South-eastern Asia, particularly Thailand, where it is a rare surname, and Philippines, where it is a very rare surname. Very seldom, ตั้งใจ is the forename as well as the last name.