We are leaving Bangkok on the 30th on a midnight flight. So we will be at the airport perhaps 3-4 hours before midnight. We bought few stuffs while in the city and had few forms for VAT refunds. Now my concern is, will the customs in the airport be open at those times in order for us to process and get our refunds back?

Thanks in advance.

I don't know about the time but they won't refund any amount under 500 Baht so if the tax due you is under that amount, just forget about the refund!