@Uwe ********
if your legalized affidavit of income shows less than 65,000.- THB a month, Immigration MIGHT allow you to use the "combination method". This means that a deposit on your Thai bank account (some immigration accept it only if it is 400,000 THB and above, some other allow less than 400,000 THB) plus the monthly income, together are above a yearly 800,000.- THB. Ask your immigration if they accept the combination method for a first "1-year extension of stay". If they do, keep in mind that on the day of application to the EOS, the deposit part must have seasoned in your account for a minimum of two months