I just sent them bank statements showing dividends and interest received of the previous 12 months. Just had to get the non english one translated and notarized.
I just entered 365 days as length of stay. I don't think they care, not sure why it is a mandatory field. They also don't ask for type of visa so they don't know how long you are allowed to stay anyway.
I am sorry if my post was confusing. I have the apprval letter for LTR feom BOI. It took almost 3 months. with that letter, passport copy etc etc I applied through the Thaievisa website for the actual visa to be issued by the Consulate in Munich. This is what I chose on my LTR application and I believe I can't change that anymore. I paid the visa fee on the Thaievisa platform (1750 EUR which is significantly more than the 50kTHB you pay if you pick it up at the visa centre on BKK)
thanks everyone. sorry if I was not clear in my post but it is not about LTR only. It could have happened with any visa.
I applied with through thaievisa with what I though was a complete set of. documents. two days after submitting and paying the fee I saw a notification on thaievisa requesting for additional documents. no email, nothing. just a missed call once and that's a week ago.