Do you need proof of a return flight when applying for a visa to Thailand?

When applying for a visa to Thailand, particularly short-term visas like the tourist visa or visa-exempt entry, proof of an onward ticket is typically required. Although you might be able to extend your stay while in Thailand, airlines often deny boarding to passengers without a confirmed flight leaving the country. Some travelers suggest purchasing a changeable ticket or using services that provide 'onward flight tickets' for a fee.