If you enter with a visa exempt stamp then exit the country either on the initial 60 days or after the 30 day extension, that stamp is now void and any re-entry starts from scratch, there is no carry over of unused days on those stamps.

I just did exactly that, update everything with new PP number and transfer stamps to new PP.

@Vin ********

... yeah correct, I forgot about that option. 😬🤷‍♂️

@Vin ********

... I know!

@Vin ********

... that will only work if it's an early AM flight and the check-in is open to allow you to pass through immigration (not customs)

What time is your flight out? If you have an early AM flight and clear immigration before midnight on the 19th, you're ok, no fine, no stamp for 1 day overstay.

@Ian *******

... his 30 days extension starts from 21 Dec as the 20th is day 60 of the visa exempt entry.

Just to clarify, a 90 day report is only required if you have stayed 90 CONSECUTIVE days in country, if you leave and return, your return day is the first day of your reset 90 days. AND your first 90 day report after returning to Thailand, must be done in person at your local IO, subsequent reports can be done online.

A 90 day report is for 90 consecutive days in country, whether you stay at the same address or move around Thailand and stay at a dozen different addresses, you still have to report. The only time it resets is when you leave the country and resets to day 1 the day you return. A caveat to that is when SOME immigration offices issue a new 1 year extension and give you a new report receipt and this restarts your 90 days. But NOTE, this is more the exception than the rule and only some IO's do this.

@Chance *******

... I'd be inclined to get a METV, Multiple-Entry Tourist Visa which is a visa that allows for unlimited entries into Thailand within a six-month validity period, with each stay capped at 60 days and extendable by another 30 days. This would work without the financial requirements of a non O.