The duration of a Thailand work visa varies from 90 days to 3 years, depending on the type of work visa. The validity of a single-entry Thailand work visa is around 90 days, during which you will be required to apply for a work permit. A Thai work permit, once issued, will have a duration of 12 months, which may vary depending on your employment contract and job role. The validity of a multiple-entry Thailand work visa is around 1-3 years, with a 90-day stay per entry.