What does Thai immigration check on arrival and do I need a return/onward ticket?

For a planned 60-day stay in Thailand, it is advisable to obtain a tourist visa in advance. Without one, border officers may ask for an onward ticket dated roughly within 29–30 days, and having to buy it during inspection can be inconvenient.

At Bangkok check-in/entry, officers asked to see the TDAC (Thailand Digital Arrival Card) and questioned the traveler in detail about how long they'd stay in Thailand and where they were heading next. To prove they'd fly home in 8 days, the traveler had to show their return flight tickets.

Separately from TDAC checks, immigration officers also watch for visa runs (leaving the country just to re-enter and extend a stay) — this practice is officially discouraged and monitored in Thailand.

At boarding in Bangkok, a passenger with a return ticket dated 2 months later was asked to show a C1-category visa — a long gap before the return flight itself triggered extra document checks.