An update for getting extensions in Phuket due to flight cancellations.
If you have not already had an extension off a tourist visa entry or visa exempt entry you can apply for a normal 30 day extension at Patong, Blue Tree or the main Phuket Town office (room 101).
If you have already had an extension from one of those entries and need longer, or needing an extension from any other form of visa entry then go to the main Phuket town office, up the stairs to room 204.
You will need a copy of your passport bio page, a copy of your entry stamp and extension stamp, a passport size photo, proof of flight cancellation due to Middle East airspace closure, an up to date TM30 filed and the extension fee of 1,900 baht.
You'll need to fill out 4 forms, TM7, STM2, STM2/1 and STM9.
If you have a letter from your embassy you will be given a 30 day extension straight away . If you do not have a letter from your embassy (most won't issue one) you fill out a declaration form along with the other forms mentioned and you will initially be given a 7 day "under consideration" stamp. You return back to room 204 a few days later and you'll be stamped for the remaining 30 days.
Patong and Blue Tree cannot process these further extensions. You must go to Phuket Town.
Unfortunately if you have already had a 7 day "denial of extension" stamp then there are no options for further extensions.
Please note this is specific to Phuket only. I am unaware of policies in place for other provinces.