What happens if you don't report 90 days Thailand?

If you don’t submit your 90-Day Report before the due date, then you still have seven days after it when you can do it. However, if you fail to do it then there is a fine of about 2,000 Thai Baht (about $65 / €60). If you were arrested during this time, and this is the reason you could not report your stay, then the fine is 5,000 Thai Baht