What is the appeals process if my one-year extension application is denied at Korat immigration?

You'll be right... As long as everything is in place. If not they'll just give you a list of jobs to complete and you go back with the corrections in a few days. Be mindful your bank account letter only lasts 7 days from date of issie

That's a pretty difficult question to answer, actually.

1. IF they deny you a one year extension of stay based on marriage to a Thai national, they *ALWAYS* tell you why they rejected it, and what you can do to get the extension of stay (i.e. updated bank statement, etc...)

2. If, for some strange reason, they rejected your extension of stay outright, I highly recommend *NOT* trying to immediately ask for an appeal. I recommending having your wife negotiate with the immigration officer to try and approve it. IF the extension of stay is appealed, it'll go to Bangkok as I understand it.