What should I do if I have a one-day overstay in Thailand due to a flight booking error?

The best way to resolve a 1-day overstay in Thailand due to a flight error is to clear immigration before midnight of your intended departure date to avoid fines. If your flight is shortly after midnight, ensure you go through immigration before the new date starts. If not, you can opt to apply for a 30-day extension at a local immigration office or simply pay the overstay fine, which is typically not enforced for a one-day overstay. Discussions also mention contacting your airline for luggage check-in times, and the implications of an overstay stamp for future entries.