Thaivisa.com, a popular portal for expats and travellers, put the question directly to Pol Col Thanasak Vongluekiat, superintendent of the Prachuap Khiri Khan and Phetchaburi Immigration office in Hua Hin.

He said that by law, all tourists and expats nationwide are required to carry their original passports with them at all times. There is no exception. Failure to carry your original passport may result in a 2,000-baht fine. A photocopy, stamped or not, or a driver's licence is not an acceptable substitute.