Is there a difference in Thai work permits? What is the difference between BOI and a regular Work Permit?

※ What is a Thailand Work Permit? A Thailand Work Permit is a legal work certificate issued by the Thai government to non-Thai nationals. It records the holder's position, job description, and employing company. Any foreigner working in Thailand must have this document. Before applying for a Work Permit, the applicant must hold a Non-B Visa. There are two ways to obtain it: 1. Enter Thailand directly with a Non-B Visa 2. Enter with another visa and then have the employing company assist in converting it to a Non-B Visa ※ What types of Thailand Work Permits are there? A. Regular Work Visa △ Applicable companies - Non-BOI companies △ Visa validity - 1 year △ Personnel ratio restrictions - strictly enforced (4 Thai nationals : 1 foreigner) B. BOI Work Visa △ Applicable companies - BOI companies △ Visa validity - 1 to 2 years △ Personnel ratio restrictions - more relaxed limits ※ What documents are required to apply for a Thailand Work Permit? 2-inch photo, original passport, educational certificates, Thai residential address Since my workplace is not in Bangkok, I have to travel a long way every time to apply. Therefore, it is essential to check multiple times before the application day to avoid missing documents that would require another trip and waiting in line again after arriving at the office.