The non-immigrant business visa must be obtained by all foreigners intending to conduct business, work, or undertake any business related activities in Thailand. It should be applied for at a Thai Embassy or Consulate abroad, prior to the foreigner entering Thailand.
The Thai one-year business visa will require you to report to the immigration office once every 90 days. Note that this reporting may also be done online now. If the visa is obtained from a Thai Embassy or Consulate abroad, the condition is that the foreigner must leave the country once every 90 days to obtain the exit-entry stamp affixed by the Thai immigration officials.
The business visa extension at Immigration Office in Thailand can be processed once you have a work permit, when your non-immigrant B visa has a validity of approximately 30 days remaining. The company must show a minimum of four full time employees registered for three months prior to the application for visa extension and an operational office. The previous year’s audit report and monthly tax filings for the past three months should be provided. Photographs of the office and staff will also be required to support the request for visa extension.