On a land-based border run (for a new 30-day tourist visa-exempt stamp), under what circumstances might a Thai Immigration official question our plans/motives? I’ve read that officials have sometimes suspected a tourist is gaming the system and then disallowed return entry, but I can’t recall any particulars. As long as it’s the first or second land-based border run in a single calendar year, and you’ve not overstayed, when—if at all—could a tourist be in jeopardy of being refused re-entry? Thanks in advance.
TLDR : Answer Summary
Tourists may be questioned by Thai Immigration officials during a land-based border run if they appear to be manipulating the visa-exemption system. Factors such as frequent border runs within a short timeframe or past overstays could raise suspicion. As long as you have not overstayed your visa and it's within the first or second run of the year, risks of refusal may still exist, especially if the officials suspect your intentions.