With the 90 day leave the country Non 0 visa,(multi entry) is there a penalty with immigration if you leave and return to Thailand a few days before the 90 day due date? On another thought if one is late leaving I believe it is 500baht a day fine, but does the late exit damage or blemish your Visa " history" for later visas etc?

No there is no issue returning 4 December if your visa ends 6 December and you will be allowed entry for 90 days from 4 December as normal for a non immigrant visa entry.

There is no current policy to review those who have overstayed when providing entry or a new visa but remember you are subject to arrest and jail during any overstay period and what has been accepted may not be at some point.

Thanks Lopburi3, a situation has come up where my "permission to stay" is Nov 5, and a flight to San Francisco was booked (non refundable) for Nov 7, 0630am. Creating an overstay of 2 calends days. From what I've read here on TV, there is usually a waiver of one overstay day, but 2 is fineable yes? It is an Early morning flight, if one were to go thru immigration at the airport Nov 6 about 2300, would that tend to likey "tick off" immigration. Just a thought. Thanks for the imput answers in advance.

You can obtain 7 days to leave with an extension application for 1,900 baht which will result in no overstay and no stamp of such in your passport. Without that believe they will fine 1,000 baht at airport and make stamp in passport. But as said unless you are in an accident during the overstay or things suddenly turn 100% it should not be a problem. Do not believe being early would tic off anyone but believe they will use your scheduled flight time.

Thanks again lopburu3, Well to be safe and " in legal standing" the 7 day extension sounds like the way to go, then I am not looking over my shoulder for a couple days. Can those 7 day extensions be acquired at Pattaya immigration by chance? Thanks again forthe enlightenment.

Believe the office is in Jomtien but yes the local office where staying is what you would use.