Can I apply for TDAC online if I have a flight tomorrow?

I wouldn’t worry about it mate , I got to BKK on Sunday , they weren’t even checking them , I even said do you want to see my TDAC and the woman said no it don’t matter .

I forgot to fill out on my return and had to take a slow walk to immigration. Strangely enough with a lot of slow programs connecting and updating it was approved by the time I got there. I don't suggest you do the same as it was very quiet at immigration. It still took 15 minutes to put 4 people through thinking that they may have some more E work to do when fulling

I went through immigration last night. Filled everything out as required. It was a piece of cake. If you have difficulty you can get help prior to going through immigration with one of the immigration assistance at a series of terminals where you can do it. Other people attempting to go through immigration without had major difficulty and scrutiny from immigration. It is a lot easier than doing it with pencil on a paper form.

It’s instantly approved in my experience. There’s also a place to register at the airport once you arrive for the people who didn’t realize they needed to.

Can be done on arrival at the airport before customs

Better yet, go to Vietnam who don't do any of this complication. As tourism to Thailand dies, Vietnam is booming.

You can do it when you arrive if you want as long as your in the 3 day window

Upto 3 days before arrival. You can complete it when you arrive in Bangkok before immigration, or while waiting to board your flight.

You can do it sat at the airport you are leaving from as it only takes minutes to do.

Only use the official website to apply, there are scammers in play.

First, don't worry, I did it and it was beautifully easy. You can do it the second you have tickets.

It’s says ‘within’ 3 days not ‘ in advance’

It actually says WITHIN 3 days, meaning 3 days at the earliest & any time after that, all the way up to just before immigration

Yes

@Arnold ****

It doesn't really say that. It's up to 3 days of entering. So from those 3 days to minutes before getting to immigration desk if necessary.

You can apply at the earliest 3 days in advance, and at the latest before you stand in front of Immigration in Thailand. :P

Yes, it is within 72 hours prior to arrival