A little information would be most appreciated.

I have always entered Thailand filling in the usual TM.6 arrival/departure card using the free 30 day on arrival stamp at immigration.

This time I am staying 116 days on a multiple o visa (doing a visa run sometime)

The question is what I should put on arrival/departure Card where it says

Length of stay ? do I just put the 90 days allowed although a visa run will be done before 90 days.

Return flight number ? if I put my return flight number on the departure card will this be a problem at immigration on the visa run or should I just leave it blank.

Or am I just being an old fart with a over active imagination.

Thanks

Since you are on a Tourist Visa, then put 60 days as your stay.

You can leave the return flight blank.

In fact you don't need to fill that part in at all, until you leave.

I admit that I do fill it in, saves time later but I never know what flight I will leave on.

The Imm officer will write your flight number on the back of the card, when he stamps it, on departure.

So no need to worry.

You arrive on a visa (non O) that allows a 90 day stamp for period of stay so that is what you write on that line.

The left side is only used on departure so don't fill in flight information as it is not expected. As a matter of fact I have never filled it in - immigration or airline must be doing it.