My 90 day report is due Oct 3. I just returned to Thailand from another country last week. Does a new 90 days start automatically on my re-entry to Thailand or do I still need to go get it done at Immigration?

The 90 days resets from the date you re-entered.

You can ignore the old report due on Oct 3rd.

Your next report of staying longer than 90 days in the country will be due 90 days from the date you entered the country including that date in the count.

Thanks, guys and/or gals. I thought that might be the case but thought I should get some "expert"opinions.

The 90 days resets from the date you re-entered.

You can ignore the old report due on Oct 3rd.