Edited to add new context:
Evidently Chaengwattana does NOT typically need a TM-27 (despite the comments below). The situation that makes this different is that I have not filed a 90 day report at my new home in Bangkok (because I've left the country multiple times and not stayed long enough for a 90 day report) so my last 90 day report from last year still reflects my old address. That's the cause of the situation and need to return next week.
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Saw a related topic and thought I'd share a cautionary tale from today's visit to Chaengwattana. Error on my part, hopefully will get it worked out. Hadn't heard of this happening before, but I'm sure it has. Immigration officer said I was the second person today with a similar experience. Had been living in Hua Hin for a couple years then started to split my time with a place I rented in Bangkok.
Did the last two extensions of stay in Hua Hin (over 50, non-O). Last year, I left my place in Hua Hin and have been living exclusively in Bangkok. Did the Bangkok TM 30 once I moved for good, but did not file a change of address TM-27 (cue foreboding music).
Today I tried to get a new extension. Had every bit of paperwork I thought was necessary, but got caught out on not having done the address change and asked why I wasn't going to the Hua Hin office for my extension. Explained I hadn't been living there for almost a year and showed them my Bangkok rental contract and TM 30.
They asked for my last rental contract and TM 30 for my place in Hua Hin (which miraculously I had with me).
All ended up with them asking me to write a letter to the supervisor explaining my move, apologizing and asking for their consideration. Have to go back next week (with freshly updated bank letter, transaction record and bank book since it'll be beyond the 7 day period of the previous letter) to see if the extension was approved by the supervisor.
Sooo... Chaengwattana definitely appears to need the TM-27 filed if you move provinces.
