Does it matter if my immigration letter for visa renewal is in Thai or English?

@Mike *****

as far as the letter is concerned I don't need to read Thai because it's a standardized letter in the bank's computer system of which an English translation exists. I have always submitted the letter in English before but yesterday I submitted it in Thai. And I have now completed my one year extension for the 20th year running. So I'm not a newbie at this. I think I just noticed that with the English version the IO would take the letter into the supervisor to make sure she understood it whereas yesterday the whole process was done by what looked like a junior clerk and maybe it sped up the process a bit.

@Jesper ******

I asked the question because although my letter has always been in English, I was just wondering what immigration prefers. Anything to make life easier for all parties concerned in getting the damned thing done.