Does an onward ticket have to be within a certain amount of days of arrival? Travellers who arrive with a setv don't have to leave within 90 days if they arrive with a visa, get an exemption and then extend a further 30 days.
TLDR : Answer Summary
The requirement for an onward ticket in Thailand does not strictly impose a specific number of days after arrival. However, travelers arriving under certain visas or exemptions may not need to leave within the usual 90-day period if they subsequently extend their stay.