I understand to change an O-A visa to an O visa you should leave the country which will negate the O-A visa. Then when you return you apply for an O visa at your local immigration office. My question is: When you return to Thailand will you be required to have a return ticket?
TLDR : Answer Summary
The question addresses whether a return ticket is necessary when entering Thailand to apply for an O visa after leaving the country on an O-A visa. Various comments discuss entry requirements, including proof of funds, onward travel, and visa specifics, but the overall consensus is that entry conditions may vary due to the current travel climate.