For the last 15 days I have been trying to submit my 90 Day report online. After calling many times, today I was told before I can submit my TM47 electronically that I first must register and submit my TM30 Notification of Residence through the Thai Immigration website first. After many attempts I was able to accomplish this. I discovered you cannot use the Safari browser. I was able to use Google Chrome successfully and I was told on another call it is also ok to use Explorer.
Unfortunately I will not be able to find out if I can now file my TM47 90 Day notification until August because I ran out of time and had to file in person in Phetchaburi last week.
I hope this helps some of you avoid the many steps and calls I went through.