Do I need a return ticket with a 90-day NON-O visa that I plan to extend for one year due to marriage to a Thai national?

When entering Thailand with a 90-day NON-O visa, typically there is no requirement for a return ticket, especially since the visa will be extended for one year on marriage grounds. While some travelers have successfully entered Thailand without a return ticket, there can be occasional misunderstandings at check-in. It's advisable to inform airline staff about your long-term visa if they question the absence of a return ticket. Some commenters mentioned that although they were not required to provide return flight details, visa applications at certain embassies may ask for such information.