How can I extend my tourist visa for 30 days in Bangkok and what documents are required?

To extend your tourist visa for an additional 30 days in Bangkok, you need to visit the Chaengwattana Immigration Office. If you originally entered Thailand with a tourist visa stamped for 60 days, you are eligible for this extension. Common requirements for the extension include submitting a completed application form and supporting documents, which may be provided by the immigration office. It's advisable to book an appointment in advance, as there can be a queue even if the appointment slots appear open.