When should I report upon arriving in Thailand and when do I need to report my address every 90 days?

When arriving in Thailand, you need to report your address using TM30 within 24 hours. Regarding the 90-day reporting requirement, this applies if you hold a long-term visa (like the Ed visa, Type-O, or work visa). You must report your address every 90 days after your arrival, but this resets if you leave the country. It's important to ensure your landlord or partner submits the TM30 upon your arrival, and remember to get a new TM30 if you leave and then re-enter Thailand, even if you are returning to the same accommodation.