Friend is due to fly back at 8.30 am on the 12th but his visa stamp is for 11th

Do they still give you one day grace at the aiport?

Yes

Depends on the border crossing.

Some will do and some not (Phuket Airport will normally fine you and Bangkok will not fine you )

Whether or not they fine you, you'll still get the little overstay dtamp in your passport, but it has not impact on future visas or non exempt entries.

I recently went through Swampy BKK with 2 day overstay....paid my 100bht...wee stamp in my Passport....Have a nice Day !!!

I recently went through Swampy BKK with 2 day overstay....paid my 100bht...wee stamp in my Passport....Have a nice Day !!!

100 baht ? Or do you mean 1000 baht ( 2 x 500 Baht )

I was told they have discretion for one day and no fine was mentioned at Swampy!

Probably. But he could always turn up at 11.45 on the 11th, and while the time away.

It is just a lottery dependent upon which side of the bed the immigration official in the line you chose arose that morning. I have been given a pass for a one-day overstay and I have been sent over to the desk to pay my fine for the same one-day overstay.