One-year B visa extension of a non-immigrant is very much alike to the one-year business visa but with minor differences. This visa type is employment-based(i.e., the applicant needs to possess a valid work permit) and even discards the necessity of leaving the country every 90 days. Furthermore, it can contribute to an application for permanent residency.
To avail of this type of Thailand visa extension, the applicant should ensure that he or she is meeting the basic minimum criteria and satisfying the minimum salary requirements for their nationality.
Before applying for business visa extension in Thailand you must ensure that you have a valid Thailand work permit and four Thai employees per visa extension application. However, the following corporate structures have to remit the requirement for the 4:1 Thai national ratio and extensions can be requested with a 1:1 ratio: