Can I change from a non-immigrant ED visa to a dependent visa without leaving Thailand?

@Nashia *******

okay now that we know you're on an extension of stay and NOT any visa you could possibly change the reason for your extension from one based on study to one based on marriage to a foreigner who legally works here (trailing spouse)

You would NOT be getting any visa, just changing the reason for your extension. Your husbands employer needs to provide documentation, you may need your marriage certificate certified by your embassy, and other documents too

SO

go to the immigration office with your husband, and someone from his company if you can to see what is required to do the change of reason to "trailing spouse" AND to see if they will even allow it.

While it might be a hassle to get out and back in to start the process to get the in coutnry Non-O and then the matching extension IF your immigration office says it can't be done like I outlined, that is gonna be your only choice 😕

There is no way you can change the reason of an issued and used visa afterwords.

But I guess you are on an Extension of Stay, big stamp you got from the Immigration Office. You have to talk with your immigration office and your husband employer if it is possible to apply next time for an Extension of Stay based on being his dependent.