Just to let people know
I was at Korat IO today for a 30 day extension based on tourist I had a Copy of : Evisa, passport page, Visa Page, TM30, TM7, and Photo.
They also asked for my Wife's ID card House Book which I though was strange.
TLDR : Answer Summary
A user shared their experience obtaining a 30-day extension of a tourist visa at Korat Immigration Office (IO) and noted that despite applying under tourism, they were asked for their Thai wife's ID card and House Book. This sparked a discussion among commenters about the requirements for extensions, with one sharing a similar experience in Nong Bua Lum Phu, emphasizing the importance of having the necessary documents ready.