What should I do about my 90-day report if I leave Thailand before it's due?

I will relate my personal experience, I came back in to thailand Nov 11, (meaning my next 90 day report would be due Feb 8th)

I filed a TM30 online while waiting in baggage claim for my luggage (even though i was returning to my primary address) 🙂

Then 2 weeks before my 90 day report due date I filed a 90 day report online and it was approved the following Monday

SO I can confirm IF you come back to the country, IF you file a TM30 updating your entry date, etc, you CAN use the online system (at least for Bangkok 🙂 )

Don’t do it

The requirement to report is only if you are in Thailand for 90 consecutive days. If you were to leave on day 89 the requirement to report finishes (even though you could technically report 15 days prior).

If you were to leave on day 93 the requirement to report is needed even though you technically have 7 days after the report is due. You may get away with not reporting but an eagled eyed officer may spot you didn’t report previously when you go to do your next one and slap a 2,000 baht fine on you.

The “clock” resets the day you return. Regardless that you may have a piece of paper in your passport or the online report system says you are due. It doesn’t know you’ve left and returned.

Yes if you're not in the country you don't report. You need to work out the dare of your next report yourself, date of entry is day 1

Then you don't Report it, IF you are out of Thailand.

The Next 90 day report begins with Day #1, on the day you return to Thailand.