In Thailand, infants do not incur overstay fines until they are 15 years old. Minors up to 18 years can be fined for overstaying but will not face blacklisting.
Infants, toddlers, babies what's in the name. Thai law use the age of the person, so till 15 years of age there is an overstay stamp but no fines, from 15 years of age till 18 years of age there is an overstay stamp and a fine, if older than 18 years of age the rules of fines and blacklist are followed. 500 Thb a day overstay with a max of 20.000 Thb and blacklist depending on days of overstay. See this picture:
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