Just for your information in regards to immigration office Nan province. As it is almost time for my yearly extension of stay based on marriage I went to the immigration office to check if something has changed and from what date I can apply for a new extension. According to the officer I can apply at max. 30 days before the end of the current extension of stay. And she also told me nothing had changed. She then handed me 2 sets of application forms. Each set "Application for extension of stay in the Kingdom" (TM47), "Acknowledgment of Penalties for Visa Overstay" and "Acknowledgment of term and conditions for permit of temporarily stay in the Kingdom of Thailand". She also explicitly told me that the bank letter has to be made on the day of application and that I needed to update my bank-book that same day. So next week I will go back for application of extension of stay based on marriage.