How important is it to show a departure ticket when entering Thailand without a firm date?

Book a flexible ticket and change when you want to return

I bought a very inexpensive ticket to Kuala Lumpur, Malaysia a few years ago when I first moved to SE Asia.

Your visa will tell you how long you can stay

Check these suggestions out,

RETURN TIX and ONWARD TIX , it’s good information all around

What type of visa ?

Long term not important.

Tourists visa need one

What visa are you entering on?

One of the most asked questions here.

You need to have a flight ticket out of Thailand within the amount of days that your initial entry allows, regardless that you can get an extension in country. It doesn’t need to be a return ticket, any ticket out of Thailand will suffice.

In theory immigration can deny you entry if you don’t but they rarely ever would, because they know you can get an extension.

Almost always the hang up will be when you try to board your plane. Many airlines will not allow you to board without an onward ticket within the number of days.

Some will let you. Many won’t. You probably don’t want to be the one scrambling to buy an onward ticket at the check in desk. Best option is a changeable ticket, and just change the date when you’re here.

Alternatively you can Google “onward flight ticket” and you’ll find a plethora of companies willing to sell you one for around $10.