What is the validity requirement for a passport when applying for a visa extension in Thailand?

@George *****

, you can apply for an extension on your passport valid for less than 6 months, but you only get the extension same as the passport validity. Then you need to apply for a new 1-year extension when you get your new passport. Your annual extension timing will be changed because of that.

@Morice ******

Cannot renew a visa. Either you get an extension inside Thailand OR you get a NEW visa outside.

@Morice ******

A visa grants you permission to cross a border. Nothing else. Depending on the visa class (or in some cases the exception from the requirement for a visa), Thailand grants a duration during which you are permitted to stay inside Thailand. This duration is indicated in your passport. Extending the permission to stay doesn't extend your visa.

So, to summarize, if you have a single entry visa and show up at the border, you will end up having permission to stay inside Thailand, but you will no longer have a valid visa.

Hope this helps.

@Morice ******

common misconception and a case of bad terminology, 😕

people don't ever renew a VISA not inside or outside the country.

inside the country you apply for an extension, it's issued for a specific time (usually a year) then you go back to the immigration office and apply for a NEW extension all over again,

and

you do that year after year after year, daisy chaining the "extensions of stay" together one after another all tracing back to the original visa that expired long ago

@Morice ******

, No you haven't. Check your stamps. Those annual stamps should say "EXTENSION OF STAY PERMITTED UP TO xxx (date)" in the first part.