The American Embassy charges $50

Get the local immigration office list of requirements - check in here for clarifications. Once you do this successfully one time - then it is a snap the next time

Time involved depends on the workload of your immigration office. Wait time varies greatly - process time once you are in front of the officer could be 30 minutes to one hour. Fee is 1900 Baht. This type of Extension of Stay is very common. In most offices if you are missing something they think is serious... Most times you would be just asked/told to go get it - come back later or next day. These Extensions have become routine.

(sorry my android operating system has a flaw - cannot currently edit comments to correct typos.

Tm.7 App Form, financial proof - Money in the bank method (800,000 THB in a Thai bank for 90 days with bank statement, bank stationary form letter validating that the account statement is yours, update Bank book for of filing with a small deposit, house lease or ownership documents, map to house, passport photos X 2... It is easy, never needed an Agent - did it 3 times. Your local immigration office will have a list of requirements. Alt Financial proof - Income Method - proof of monthly income to meet or exceed 65,000 Baht equivalent a month - from a year source outside Thailand. For Americans we can get an Income Affidavit / Letter from the American Embassy - Bkk. Make online appointment - and download the form. No income proof required.

Go to Immigration - get a Certificate of Residence. To get it - you need proof of residence - lease - rental agreement. Or Guesthouse receipts.

One important point. From my direct experience - Once the Thai Registered Company is set up, depending on valuation 2 to 4 Thai Employees are required. For the most Work Permit and the 90 Day B visa the Foreign owner must show by receipt that the Social Security payments have been made for the Thai Employees. Then when applying for a One Year Extension of the B Visa One must show S.S. Payments, Withholding Income Tax payments on the Employee and for the Foreigner Shareholder Applicant. Then add a big stack of company formation and certification documents and many others. My App Stack was at least 8 CM thick - two copies. Then after the provisional stamp (wait one month for final stamp) - an I/O comes to your place of business to inspect and check and see and take photos of the Thai Employees. Every B Visa Extension App here in the South goes to Bkk for sign off (the 30 day wait)

To actually roll out it is complicated a d expensive - several months to get done. Plus monthly expenses after it is done Got 100,000 Baht to get started?

If you believe it - then yes

Or you would form you own company and doe the same with you as a Shar holder / Director - then Work Permit and B Via application using the services of an Agent - Accountant and Lawyer