If foreigners are traveling in Thailand or living here, and an embassy or consulate has confirmed and requested that the person stay in Thailand to work or be an intern, documents are required to apply for a visa extension, as follows:

Requirements 

1. Certified and requested by the embassy or consulate;
2. In the case of an internship, a temporary resident visa is required.

Required Documents

1. Application form TM.7;
2. Copy of the applicant's passport;
3. Letter of confirmation for extension of stay from the embassy or the consulate in Thailand;
4. In the case of an internship, a copy of the work permit must be attached.