Is an outbound flight needed for a 6-month stay in Thailand under a long-term visa?

The necessity of an outbound flight for a 6-month stay in Thailand varies based on individual experiences and specific visa types. While some users report that they've never been asked for proof of onward travel by Thai immigration, others have encountered requests for a return ticket from airline check-in agents. It's noted that the Departure Details on the DTAC (Thai Departure Card) can be left blank. Generally, travelers with non-tourist visas like the DTV (long-term visa) may have less stringent requirements compared to those with tourist visas. Nevertheless, travelers are advised to be prepared, as airline policies may differ.