I was lucky. Except during Covid, I rarely travelled domestically with my PP and just used my Drivers Licence - including checking in on domestic flights. Last week in Chiang Mai, I still had my passport wallet in my suitcase from a couple of February trips the Legalization Office of the Dept of Foreign Affairs in Pattaya Central as I had forgotten to put it back in my desk when returning from that trip. I don't recall specifically if the hotel in Bangkok a week that trip had the "no PID no DL" signage up because I had my passport with me anyway to go to my embassy. I would suggest people do not travel without their passport. I have seen, as others have mentioned, those scanned plastic copies of one's passport but I don't know if they're still acceptable to hotels. Also, in the hotel in Bueng Kan, I was asked to sign and date a photocopy of my passport as well. I don't recall ever having to do that previously, or when using m y DL.
