I need to do a 90-day report to Immigration on September 21 for my retirement extension. I'm leaving on a holiday to Australia on September 22.

Do I need to report?

They could check it on you next report and see you actually stayed longer than 90 days without a report so it would be a 2,000 baht chance - suspect most would let it go but a few might love to 'tell you so' and raise the fine flag. You do have 7 days late allowed when making a report but suspect they might feel that is only if you make a report within that time period.

Thanks!

I'll just play it safe and report when I apply for a re-entry permit next week.