Can I extend my tourist visa immediately upon arrival in Thailand?

The ability to extend a tourist visa immediately upon arrival in Thailand depends on the immigration office. While some offices allow extensions right after arrival, others may require that you file a TM30 form first. Generally, it is best to approach the extension request within the last week of your original visa or entry. If you're considering extending a visa exemption, most offices typically allow extensions at any time, but some have stricter rules. Alternatively, you may opt to pay a fine for overstaying, but there is a risk involved regarding future visits.