When you are in Thailand for the purpose of performing work related to investments approved by a ministry, bureau, or department, the requirements are as follows:
1. You must hold a Non-Immigrant Visa;
2. Your request must be confirmed and supported by the relevant ministry, bureau, or department.
Required documents to be submitted to the Immigration Office are as follows:
1. TM.7 form;
2. Copy of the applicant's passport;
3. Copy of work permit;
4. Confirmation letter from relevant ministry, bureau, or department.
Source: Immigration Office
Tel. 1178 / 0 2572 8500