I got caught a little over a year ago and could not settle it "out of court" (believe me, I tried). From what I understand, penalties depend on which court you are brought to. In my case, I was caught in Asoke and brought to Lumpini Police Station who then decided in which court I would be prosecuted.
Below is the penalty, which apparently is the harshest it gets for a first time DUI:
- THB 20'000 bail to get out of jail and come back to court on Monday (was fully refunded)
- THB 8'000 fine (THB 6'000 if caught on a motobike, irrespective of how much you are above the limit)
- 6 months licence suspension (irrespective of how much you are above the limit)
- 3 months of jail on probation for 2 years (irrespective of how much you are above the limit)
- 4 yearly visits to a probation officer (irrespective of how much you are above the limit)
- 12 hours of community service (only for a certain amount of alcohol in the blood, but not sure how much)
I legally work here and there never was any mention of deportation. I have since then renewed my WP and visa with no problem. They give you a fair warning on your first DUI and as long as you don't repeat the same mistake, you will be fine...