How long can someone who received a red stamp at Krabi airport be banned from re-entering Thailand?

@Ellie ******

brings up an excellent point (y)

NOT all borders will let people who get 90 day visa exempt entries stamp in at them.

OKay, first off he didn't get black listed :/ He got denied entry.

He got that because Brazilians get 90 days when the stamp in for free BUT they can't just come in and out all the want on those free 90 day stamps <- meaning they can't LIVE here on them.

He can try to enter on another 90 day visa exempt entry by land (make sure he has proof of funds 20K baht or the equivalent in CASH), proof of onward travel (in 90 days) and proof of lodging.

OR

He can buy a tourist visa while he's in KL then cross in by land.

He has a HIGH chance of being denied entry flying in on a tourist visa or a 90 day visa exempt entry.

Brazilians can get 90days on a bilateral agreement not exempt entry. Did he get real SETV at any consulate around here or he was just about to enter Thailand without buying visa?

And what does his "red stamp' say exactly?

Christian ...with a little info...we can suggest a path to reenter Thailand. Good Luck to your friend.

What is a "red stamp"? What writing does he have?

What kind of visa was he on?

Or was he trying to enter visa exempt?

Nationality/passport?

Where is he now?

Where was he coming from?