Originally Posted by
dozerman94
I tried something similar last year for the 11pm flight, they opened the counter ~3 hours before the flight time. BKK is particularly good for lounge hopping, plenty of options
If you have your boarding pass from online checkin and don't need to check a bag you can go airside even earlier.
Can confirm this. 3 hours, plus some minutes in my experience. But if there are other TK flights departing earlier on the same day (e.g., at 8 or 9 o'clock), the check-in counter will be open for them, and OP will /probably/ also be able to check-in.