Do I need to file my 90-day report if I'm leaving Thailand just after it's due?

Make sure to have a re-entry permit in your passport. That keeps your extension of stay valid upon return to Thailand.

As it appears that you did get the one year extension of stay in 2022.

That's not how 90 day reporting works 😕

The rule is IF you're here on the day your report is due you file one 😮

That "up to 7 days after the report is due" is NOT a grace period where if you're leaving during that time you don't have to report 😉 it's a window of opportunity TO report (from 2 weeks before the due date until 1 week after) 🙂

You are correct, if you stamped in here on Dec 10th your 90 day report would be due on Mar 9th (89 days from the date you stamped in)

I personally would file a 90 day report (BUT that's just how I am)

If you don't file one, there's a chance when you come back and go to do the NEXT 90 day report they see you failed to apply for the previous one and left the country AFTER it was due and they could charge you a 2000baht failure to file on time fine before they let you apply again. OR they could not even notice it and you would be fine.

Face it the worst that will happen if you don't file and get caught on it during the next 90 day report would be a 2000baht fine, it doesn't go up, so I will leave it to you to decide