Terry Morgan But don't forget the window when reporting online, 15 days before the due date (counting from the due date) until the due date. If you're one day late, you need to do it in person. I'm staying in walking distance from Jomtien immigration,meaning I don't need to report online.
I mentioned the cheapest option which is based on marriage. You just need ฿40k/month or ฿400k in a bank account. I live in Thailand as a retiree since many years. I don't need any advice about financial requirements.