Can you drink tap water in Thailand, or is the bottled habit just caution?

We are not going to answer this one, and the reason matters: we do not have an authoritative source on water quality by area, and guessing on a health question is how sites lose the right to be trusted on the ones we can answer. What is clear is that almost everyone defaults to bottled or filtered water, including residents, and that ice in most places comes from commercial suppliers rather than taps. The wider health and insurance picture is the part we do source: https://meetlocale.com/guides/is-thailand-safe-to-travel-alone If you live there, what do you actually drink at home, and does it vary by city?