If you are applying for a Non-O multi entry from the UK. You need to use this Royal Thai Embassy online portal.
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There is no Police check.
There is no Health Insurance requirement
After approval you can come on a one way ticket as well.
What do you need for the online portal?:
Photo copy of your passport. Saved in a JPEG format.
Two passport photos.
A bank statement no older than 3 months
Marriage certificate UK or Thai no need for translation.
There is no need to send original documents to the embassy any longer. Just the photo copies and two photos. My wife owns a blue book and 8 full land titles. So I photo copied them and sent them as well.
I sent the copies to the Embassy next day delivery and included a prepaid return envelope for my visa. My wife wrote a letter in Thai explaining we were relocating back to Thailand permanently. I filled out the online application in 30 minutes on the Sunday checked and submitted. Posted on a Monday. Approved Wednesday and Visa in had by the Friday.
I found the whole experience very easy and the Royal Thai Embassy staff were so helpful. Been here now 3 years with my wife and daughter. Best thing ever coming to Thailand. I know we are only guests here but what an honour to live here.