Public schools are free for Thai citizens or those who were born in Thailand, and have one Thai parent. Expatriate children must pay fees when attending a public school, although the fees for public schools are usually cheaper than those of international schools. You need your child's birth certificate and the Tabien Baan (your house registration document) to enrol your child in a public school.
Although there are some public schools where over 50% of classes are conducted in English, most expatriates send their children to internationals school due to the smaller class sizes and less learning by rote.