TL;DR:All foreigners staying over 90 consecutive days must report every 90 days (TM.47); file in person, by mail, or via the Immigration Bureau’s e‑90day portal and keep the confirmation.
If you stay in Thailand for more than 90 consecutive days you must submit a 90‑day report (TM.47) to Thai Immigration every 90 days — this applies to almost all foreign nationals regardless of visa type (exclusions: certain diplomats, transit/border-pass holders). File within 15 days before or up to 7 days after each 90‑day mark to avoid fines. You can file: 1) in person at any Immigration office (bring passport, passport copies, visa/entry stamp, previous 90‑day slip and completed TM.47); 2) online via the Immigration Bureau’s e‑90day portal (often requires you to have done at least one prior in‑person report); or 3) by mail to the Immigration Bureau or through a representative with the same documents. Keep the receipt/confirmation slip as proof. If the online system or mail is unreliable, report in person. For official details and forms see the Thai Immigration Bureau and Thai Embassy guidance.
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