For Germans coming to Thailand on a retirement 90 O s/m Visa please be advised to contact the Embassy (Berlin) or Generalkonsulat (Munich or Frankfurt) before applying for a visa. The regulations have changed and there is a lot more paperwork to bring by!
In the case of my Mom coming to stay with me for 3 Month now in December, they now need in addition to the usual a "Letter of Invitation", copy of my passport (main page and depending on the officer copy of my Visa and Receipt of Notification), a contact person/guarantor in Grmany, copy of your pension statement (no less than 1200 € p/M) or bank statement of the last three month with never going below 5000 €.
So people with condos, houses and longterm leases please inform yourself which paperwork/copies you have to bring by in order to get your visa!!!!
The answer as to why they make it so complicated now, meeting international visa standards!