1 hour ago, ubonjoe said:

It is has to be translated to English or Thai if it is not in English.

my mistake: of course, the certificate will be in English, it doesn't need to be translated in Thai ? 

 

And one month in advance is Ok ? Thanks

Edited December 15, 20196 yr by Aforek

20 minutes ago, Aforek said:

my mistake: of course, the certificate will be in English, it doesn't need to be translated in Thai ? 

And one month in advance is Ok ? Thanks

No need for a translation.

One month will be accepted.

On 11/21/2019 at 6:51 AM, Aforek said:

,,,

( btw, is there an other place where I can have my tourist visa changed in O-retirement , just to avoid to leave Thailand again ? ) 

...

There is actually no need to go to Savannakhet or Penang to get a 90-day Non Imm O - retirement Visa.

You can do it at your local IO.  But you need to apply at least 15 days (some require 21 days) before your Tourist Visa expires.  Attached a link with the requirements:

https://www.immigration.go.th/content/service_80