Plain-language overview only—not legal advice. Rules, quotas, and forms change; double-check dates, fees, and eligibility with Thai Immigration or a qualified adviser before you book flights or quit a job.
Thailand separates how you enter (visa exemption stamp, tourist visa, or a non-immigrant visa obtained abroad or converted in-country) from what you do after arrival: extensions of stay, re-entry permits, address notifications, and—when working— work permit rules enforced by the Ministry of Labour, not the immigration desk alone.
Most long-stay residents cycle through a provincial immigration office for extensions and the periodic 90-day report (where required), while employers and landlords trigger parts of the address-notification (TM30) workflow. Treat immigration, labour, and your lease as three lanes that have to line up.